This classification was based on the cellular composition of the intratumoral immune infiltrates, the gene expression level of CTLA-4, PD-1, PD-L1, cancer antigenomes comprising neoantigens, tumor heterogeneity, and predetermined sets of genes like HLA molecules, immunostimulators, and immunoinhibitors (Figure 7B) (12–14). This evidence concerns the gene CTLA4 and cancer.