PIK3CA and breast cancer: KEGG pathway analysis revealed that it was mainly concentrated in the prolactin signaling pathway, aldosterone-regulated sodium reabsorption, chemical carcinogenesis (receptor activation), type II diabetes mellitus, breast cancer, human cytomegalovirus infection, prostate cancer, endocrine resistance, phosphatidylinositol-3 kinase (PI3K)-Akt signaling pathway, mTOR signaling pathway, and insulin resistance (Fig. 5A and B).