Finally, molecular activity prediction of the canonical pathway estrogen receptor signaling defined by the Ingenuity Knowledge Base included three of the six (TP53, PTEN, NOTCH1, AKT1, PIK3CA, and RB1) commonly downregulated genes with loss of function mutations in both molecular subtypes of breast cancer (TNBC and HER2−). This evidence concerns the gene ESR1 and breast cancer.