We then calculated the BC TMB associated with CCNB1 for each patient in the TCGA and GTEx databases, and we found that the expression of CCNB1 in luminal A BC cell lines was positively correlated with TMB, P < 0.05; while in BC cell lines the expression in luminal B, Her2+, and Basal like BC cell line was not statistically significant (Supplementary Figure 1A). This evidence concerns the gene CCNB1 and breast cancer.