PDCD1 and neoplasm: The correlation analysis of YTHDF1, YTHDF2 and tumor infiltrating lymphocytes in the non-treatment group is summarized in Figure 1 In the adenocarcinoma group not receiving PD-1/PD-L1 inhibitor, the immunohistochemical expression of YTHDF1 was significantly negatively associated with CD4 and CD8 and positively correlated with FOXP3 expression.