The mutation frequencies of TP53 (p = 4.81 E‐23), ERBB2 (p = 1.57 E‐48) and CDK12 (p = 2.67 E‐30), TOP2A (p = 1.65 E‐05), SPOP (p = 0.00016), RARA (p = 3.74 E‐06), PIK3CA (p = 0.0402), PTK2 (p = 0.00082), and FAT4 (p = 0.0400) were significantly different among the four BC subtypes (Figure 3), and so the other genes in these four subtypes in Table S1. This evidence concerns the gene SPOP and breast cancer.