X0306 4 2021-02-01 0 0001726445 Seer, Inc. SEER 0001340097 Invus Public Equities, L.P. 750 LEXINGTON AVENUE, 30TH FLOOR NEW YORK NY 10022 0 0 1 0 0001766952 Artal Treasury Ltd P.O. BOX 165 SUITE 4, BOROUGH HOUSE, RUE DU PRE ST. PETER PORT Y7 GYI 3JJ GUERNSEY 0 0 1 0 0001218180 Artal International S.C.A. VALLEY PARK, 44, RUE DE LA VALLEE LUXEMBOURG N4 L-2661 LUXEMBOURG 0 0 1 0 0001522131 Artal International Management S.A. VALLEY PARK, 44, RUE DE LA VALLEE LUXEMBOURG N4 L-2661 LUXEMBOURG 0 0 1 0 0001053906 Artal Group S.A. VALLEY PARK, 44, RUE DE LA VALLEE LUXEMBOURG N4 L-2661 LUXEMBOURG 0 0 1 0 0001283968 Westend S.A. VALLEY PARK, 44, RUE DE LA VALLEE LUXEMBOURG N4 L-2661 LUXEMBOURG 0 0 1 0 0001841311 Wittouck Amaury VALLEY PARK, 44, RUE DE LA VALLEE LUXEMBOURG N4 L-2661 LUXEMBOURG 0 0 1 0 0001460840 Stichting Administratiekantoor Westend CLAUDE DEBUSSYLAAN, 46 1082 MD AMSTERDAM THE NETHERLANDS P7 NETHERLANDS 0 0 1 0 0001340096 Invus Public Equities Advisors, LLC 750 LEXINGTON AVENUE 30TH FLOOR NEW YORK NY 10022 0 0 1 0 Class A Common Stock 2021-02-01 4 S 0 252545 64.153 D 5588366 D This amount represents the $67.00 secondary public offering price per share of Class A common stock of Seer, Inc., less the underwriting discount of $2.847 per share for shares sold pursuant to an underwritten public offering. The shares are held directly by Invus Public Equities, L.P. The general partner of Invus Public Equities, L.P. is Invus Public Equities Advisors, LLC. Artal Treasury Ltd is the managing member of Invus Public Equities Advisors, LLC. Artal Treasury Ltd is a wholly owned subsidiary of the Geneva branch of Artal International S.C.A. The managing partner of Artal International S.C.A. is Artal International Management S.A., which is a wholly owned subsidiary of Artal Group S.A. Westend S.A. is the parent company of Artal Group, S.A., and the majority stockholder of Westend S.A. is Stichting Administratiekantoor Westend ("Stichting"). Mr. Amaury Wittouck is the sole member of the board of Stichting. Each of the Reporting Persons, other than Invus Public Equities L.P., disclaims beneficial ownership of the securities held by the other Reporting Persons, except to the extent of such reporting person's pecuniary interest therein, and, pursuant to Rule 16a-1(a)(4) under the Exchange Act, each of the reporting persons (other than to the extent it directly holds securities reported herein) states that the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of all of the reported securities for purposes of Section 16 of the Exchange Act or for any other purpose. See Signatures Included in Exhibit 99.1 2021-02-03