As shown in Figures 3A–F, we found that the PD-L2, PD-1, LAG3, TIGIT, CTLA4 expression levels in subtype C1 were higher than in C2, indicating that patients in subtype C1 with a high expression of immune checkpoint inhibitors were more likely to form an immunosuppressive microenvironment, further leading to tumor immune escape (Dunn et al., 2002). This evidence concerns the gene CTLA4 and neoplasm.