GZMB and cancer: Of note, IFN-I-related immune escape has been previously associated with the upregulation in cancer (stem) cells of (1) PD-L1 and LGALS9 (ref. 16), (2) nitric oxide synthase 2, which favors the recruitment of regulatory cells48 and (3) SERPINB9, which inhibits granzyme B activity and thus CD8+ T cell cytotoxicity49.