PSNL · Personalis, Inc.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 23, 2025.

The shares subject to the option are fully vested and exercisable.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 23, 2025.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 23, 2025.

The price reported above reflects the weighted average price of the shares sold. The sale price ranged from $15.01 to $15.45 per share. Upon request from the SEC staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

The price reported above reflects the weighted average price of the shares sold. The sale price ranged from $15.00 to $15.24 per share. Upon request from the SEC staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

The shares subject to the option are fully vested and exercisable.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

The option vested and became exercisable over the three-year period commencing April 15, 2024, with 1/36th of the shares subject to the option vesting each month of continuous service thereafter.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The shares subject to the option are fully vested and exercisable.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The price reported above reflects the weighted average price of the shares sold. The sale price ranged from $13.00 to $13.30 per share. Upon request from the SEC staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

The option vested and became exercisable over the three-year period commencing April 15, 2024, with 1/36th of the shares subject to the option vesting each month of continuous service thereafter.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The shares subject to the option are fully vested and exercisable.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The shares subject to the option are fully vested and exercisable.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

The price reported above reflects the weighted average price of the shares sold. The sale price ranged from $13.00 to $13.36 per share. Upon request from the SEC staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The shares subject to the option are fully vested and exercisable.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The price reported above reflects the weighted average price of the shares sold. The sale price ranged from $12.00 to $12.10 per share. Upon request from the SEC staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

The option vested and became exercisable over the three-year period commencing April 15, 2024, with 1/36th of the shares subject to the option vesting each month of continuous service thereafter.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

The price reported above reflects the weighted average price of the shares sold. The sale price ranged from $11.00 to $11.12 per share. Upon request from the SEC staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The shares subject to the option are fully vested and exercisable.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 7, 2025.

The price reported above reflects the weighted average price of the shares sold. The sale price ranged from $11.50 to $11.71 per share. Upon request from the SEC staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

The price reported above reflects the weighted average price of the shares sold. The sale price ranged from $11.00 to $11.05 per share. Upon request from the SEC staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price within the range set forth in this Form 4.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

The option vested and became exercisable over the three-year period commencing April 15, 2024, with 1/36th of the shares subject to the option vesting each month of continuous service thereafter.

The sales and option exercise reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on December 17, 2025.

Each share is represented by a restricted stock unit ("RSU"). Each RSU represents a contingent right to receive one share of the Issuer's common stock upon settlement. 100% of the shares subject to the RSU shall vest on the earlier of the one-year anniversary of the grant date or the day prior to the Company's next annual meeting of stockholders occurring after the grant date, subject to the reporting person's Continuous Service (as defined in the Company's 2019 Equity Incentive Plan (the "2019 Plan")) through the vesting date. In the event of a Change in Control (as defined in the 2019 Plan), the shares underlying the RSU shall vest immediately prior to the effectiveness of such Change in Control.

Each share is represented by a restricted stock unit ("RSU"). Each RSU represents a contingent right to receive one share of the Issuer's common stock upon settlement. 100% of the shares subject to the RSU shall vest on the earlier of the one-year anniversary of the grant date or the day prior to the Company's next annual meeting of stockholders occurring after the grant date, subject to the reporting person's Continuous Service (as defined in the Company's 2019 Equity Incentive Plan (the "2019 Plan")) through the vesting date. In the event of a Change in Control (as defined in the 2019 Plan), the shares underlying the RSU shall vest immediately prior to the effectiveness of such Change in Control.

Each share is represented by a restricted stock unit ("RSU"). Each RSU represents a contingent right to receive one share of the Issuer's common stock upon settlement. 100% of the shares subject to the RSU shall vest on the earlier of the one-year anniversary of the grant date or the day prior to the Company's next annual meeting of stockholders occurring after the grant date, subject to the reporting person's Continuous Service (as defined in the Company's 2019 Equity Incentive Plan (the "2019 Plan")) through the vesting date. In the event of a Change in Control (as defined in the 2019 Plan), the shares underlying the RSU shall vest immediately prior to the effectiveness of such Change in Control.

This amendment corrects the number of shares of Common Stock reported as beneficially owned by the Reporting Person on the Form 4 filed on May 14, 2026.

Each share is represented by a restricted stock unit ("RSU"). Each RSU represents a contingent right to receive one share of the Issuer's common stock upon settlement. 100% of the shares subject to the RSU shall vest on the earlier of the one-year anniversary of the grant date or the day prior to the Company's next annual meeting of stockholders occurring after the grant date, subject to the reporting person's Continuous Service (as defined in the Company's 2019 Equity Incentive Plan (the "2019 Plan")) through the vesting date. In the event of a Change in Control (as defined in the 2019 Plan), the shares underlying the RSU shall vest immediately prior to the effectiveness of such Change in Control.

100% of the shares subject to the option shall vest on the earlier of the one-year anniversary of the grant date or the day prior to the Company's next annual meeting of stockholders occurring after the grant date, subject to the reporting person's Continuous Service (as defined in the 2019 Plan) through the vesting date. In the event of a Change in Control (as defined in the 2019 Plan), the shares underlying the option shall vest and become exercisable immediately prior to the effectiveness of such Change in Control.

Each share is represented by a restricted stock unit ("RSU"). Each RSU represents a contingent right to receive one share of the Issuer's common stock upon settlement. 100% of the shares subject to the RSU shall vest on the earlier of the one-year anniversary of the grant date or the day prior to the Company's next annual meeting of stockholders occurring after the grant date, subject to the reporting person's Continuous Service (as defined in the Company's 2019 Equity Incentive Plan (the "2019 Plan")) through the vesting date. In the event of a Change in Control (as defined in the 2019 Plan), the shares underlying the RSU shall vest immediately prior to the effectiveness of such Change in Control.

Each share is represented by a restricted stock unit ("RSU"). Each RSU represents a contingent right to receive one share of the Issuer's common stock upon settlement. 100% of the shares subject to the RSU shall vest on the earlier of the one-year anniversary of the grant date or the day prior to the Company's next annual meeting of stockholders occurring after the grant date, subject to the reporting person's Continuous Service (as defined in the Company's 2019 Equity Incentive Plan (the "2019 Plan")) through the vesting date. In the event of a Change in Control (as defined in the 2019 Plan), the shares underlying the RSU shall vest immediately prior to the effectiveness of such Change in Control.

100% of the shares subject to the option shall vest on the earlier of the one-year anniversary of the grant date or the day prior to the Company's next annual meeting of stockholders occurring after the grant date, subject to the reporting person's Continuous Service (as defined in the 2019 Plan) through the vesting date. In the event of a Change in Control (as defined in the 2019 Plan), the shares underlying the option shall vest and become exercisable immediately prior to the effectiveness of such Change in Control.

100% of the shares subject to the option shall vest on the earlier of the one-year anniversary of the grant date or the day prior to the Company's next annual meeting of stockholders occurring after the grant date, subject to the reporting person's Continuous Service (as defined in the 2019 Plan) through the vesting date. In the event of a Change in Control (as defined in the 2019 Plan), the shares underlying the option shall vest and become exercisable immediately prior to the effectiveness of such Change in Control.

100% of the shares subject to the option shall vest on the earlier of the one-year anniversary of the grant date or the day prior to the Company's next annual meeting of stockholders occurring after the grant date, subject to the reporting person's Continuous Service (as defined in the 2019 Plan) through the vesting date. In the event of a Change in Control (as defined in the 2019 Plan), the shares underlying the option shall vest and become exercisable immediately prior to the effectiveness of such Change in Control.

100% of the shares subject to the option shall vest on the earlier of the one-year anniversary of the grant date or the day prior to the Company's next annual meeting of stockholders occurring after the grant date, subject to the reporting person's Continuous Service (as defined in the 2019 Plan) through the vesting date. In the event of a Change in Control (as defined in the 2019 Plan), the shares underlying the option shall vest and become exercisable immediately prior to the effectiveness of such Change in Control.

Each share is represented by a restricted stock unit ("RSU"). Each RSU represents a contingent right to receive one share of the Issuer's common stock upon settlement. The RSUs vest in 6 equal semi-annual installments with the first installment vesting on September 15, 2026.

Includes 2,500 shares acquired under the Issuer's Employee Stock Purchase Plan on October 31, 2025.

The shares subject to the option vest in 36 equal monthly installments with the first installment vesting on April 15, 2026.

The shares subject to the option vest in 36 equal monthly installments with the first installment vesting on April 15, 2026.

Each share is represented by a restricted stock unit ("RSU"). Each RSU represents a contingent right to receive one share of the Issuer's common stock upon settlement. The RSUs vest in 6 equal semi-annual installments with the first installment vesting on September 15, 2026.

The shares subject to the option vest in 36 equal monthly installments with the first installment vesting on April 15, 2026.

Each share is represented by a restricted stock unit ("RSU"). Each RSU represents a contingent right to receive one share of the Issuer's common stock upon settlement. The RSUs vest in 6 equal semi-annual installments with the first installment vesting on September 15, 2026.

Each share is represented by a restricted stock unit ("RSU"). Each RSU represents a contingent right to receive one share of the Issuer's common stock upon settlement. The RSUs vest in 6 equal semi-annual installments with the first installment vesting on September 15, 2026.

The shares subject to the option vest in 36 equal monthly installments with the first installment vesting on April 15, 2026.

This amount represents the vesting of a performance stock option granted on March 15, 2024, following the satisfaction of a specified reimbursement milestone.