Filing Summary for Atlas Venture Fund VIII, L.P. regarding Integral Ad Science Holding Corp.

This filing is an amendment to a Schedule 13G by Atlas Venture Fund VIII, L.P., Atlas Venture Associates VIII, L.P., and Atlas Venture Associates VIII, Inc. concerning their beneficial ownership of Integral Ad Science Holding Corp. common stock. As of December 23, 2025, none of the reporting persons beneficially own any shares of the Issuer's Common Stock. The filing indicates that the reporting persons do not hold more than 5% of the class of securities. The principal business address for all reporting persons is 56 Wareham Street, 3rd Flr, Boston, MA 02118. The filing was made on December 23, 2025.