Amendment: SEC Form SCHEDULE 13D/A filed by Seer Inc.

Item 4 is hereby amended to add the following: On April 13, 2026, the Reporting Persons submitted a non-binding proposal to acquire 100% of the equity of the Issuer at a purchase price of $2.25 per Share in cash, representing a 33% premium to the Issuer's most recent closing price, plus a contingent value right representing the right for stockholders to receive 80% of the net proceeds received from any license, sale or other disposition of the Issuer's business and assets, including PrognomiQ (the "Proposal"). The Proposal is only subject to limited confirmatory due diligence and is based on the availability of at least $215 million of net cash and cash equivalents at closing and is not subject to any financing conditions. The Reporting Persons requested a response regarding the Issuer's board of directors' (the "Board") willingness and availability to discuss the Proposal no later than 5:00pm ET on April 22, 2026, at which point the Proposal will expire. Also on April 13, 2026, Mr. Radoff delivered a letter to the Issuer nominating Howard H. Berman, Joshua S. Horowitz and Luis E. Rinaldini (the "Nominees") for election to the Board at the Issuer's 2026 annual meeting of stockholders (the "Annual Meeting"). Also on April 13, 2026, the Reporting Persons issued a press release (the "Press Release"), which included a copy of the Proposal delivered to the Board and announced the nomination of the Nominees for election to the Board at the Annual Meeting. The foregoing descriptions of the Proposal and the Press Release do not purport to be complete and are qualified in their entirety by reference to the full text of the Press Release, which is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

Item 5(c) is hereby amended and restated to read as follows: There have been no transactions in the securities of the Issuer by the Reporting Persons since the filing of Amendment No. 1 to the Schedule 13D.

Item 6 is hereby amended to add the following: On April 12, 2026, (a) Radoff (as defined in the initial Schedule 13D), (b) JEC (as defined in the initial Schedule 13D) and (c) Dr. Berman and Messrs. Horowitz and Rinaldini (collectively, the "New Parties") entered into an amended and restated group agreement (the "Amended and Restated Group Agreement") with respect to the Issuer pursuant to which, among other things, (i) that certain group agreement, dated February 20, 2026, between Radoff and JEC was superseded in its entirety, (ii) the parties agreed to the joint filing on behalf of each of them of statements on Schedule 13D with respect to the securities of the Issuer to the extent required by applicable law, (iii) the parties agreed to solicit proxies for the election of certain persons nominated for election to the Board at the Annual Meeting (including those nominated by or on behalf of Radoff or JEC), (iv) the parties agreed not to transact in securities of the Issuer without the prior written consent of Radoff and JEC for so long as the Issuer's tax benefit preservation plan, dated as of February 26, 2026 (the "NOL Pill"), remains in effect; provided, that each New Party further agreed not to enter into any transactions in the securities of the Issuer without the prior written consent of Radoff and JEC notwithstanding any potential termination of the NOL Pill and (v) Radoff and JEC agreed to jointly pay all expenses and costs (including all legal fees) incurred in connection with the group's activities on a pro rata basis based on the number of Shares beneficially owned in the aggregate by such party. The Amended and Restated Group Agreement is attached hereto as Exhibit 99.2 and is incorporated herein by reference. Each of the Nominees has granted Mr. Radoff a power of attorney (each, a "Power of Attorney") to execute certain SEC filings and other documents in connection with the solicitation of proxies at the Annual Meeting. A form of the Power of Attorney is attached hereto as Exhibit 99.3 and is incorporated herein by reference.

Item 7 is hereby amended to add the following exhibits: 99.1 - Press Release, dated April 13, 2026. 99.2 - Amended and Restated Group Agreement, dated April 12, 2026. 99.3 - Form of Power of Attorney.