RSAD2 and neoplasm: In Fig. 5b, our DEG analysis of IFN signal pathway-related genes showed significant upregulation of a panel of immunoreactive genes including OASL, GBP4, SAMD9L, IFIT3, RSAD2, IFI44, STAT2, MX1, and IFIF27 upon I-DXd treatment (Fig. 5c, d), indicating that I-DXd effectively ameliorates tumor immune microenvironment by activating type I IFN responses.