PRF1 and neoplasm: In contrast, the top three effectors associated with αPD‐1 were GZMB, PRF1, and IFNG (Figure 4H–J), all of which were reported to play important roles in CD8+ T mediated anti‐tumor immunity.[24, 25] The transcription level and the proportion of PITs expressing these three molecules were elevated under αPD‐1 treatment (Figure S7C,D, Supporting Information).