PDCD1 and neoplasm: In the process of APOBEC mutagenesis, the increased expression of important immune checkpoint molecules, including PDCD1, TIGIT, HAVCR2, LAG3 and IDO1, and the elevated CYT score, which serves as cytotoxic effects and anti-tumor response, were highly suggestive of better immunotherapy response (Figures S2G and S2H).