The expression levels of CCND1, VEGFA, AURKB, HDAC1, HSP90AA1, and HSP90AB1 were positively correlated with immune cell infiltration levels, whereas the expression levels of SIRT2 and CASP9 were negatively correlated with the tumor purity of BRCA (Figure 3(b)). This evidence concerns the gene CASP9 and neoplasm.