Some are mutated or altered at high frequency (e.g., TP53, PIK3CA, MYC, CCND1, ERBB2) whilst most are affected infrequently, with only 39/147 (26.5%) of these driver genes being altered in 5% or more of the TCGA breast cancer samples (Figure 1A). This evidence concerns the gene CCND1 and breast carcinoma.