PIK3CA and breast cancer: To enhance the BC‐specificity of the analysis, we focus on the 23 genes that we found to be common to these three gene lists (Figure 8A): AKT1, ARID1A, ARID1B, BAP1, BRCA1, BRCA2, CASP8, CDH1, CDKN1B, CTCF, ERBB2, ESR1, FOXA1, GATA3, MAP2K4, MAP3K1, NCOR1, PIK3CA, RB1, SALL4, SMARCD1, TBX3, TP53 (Table S6, Supporting Information).