PIK3CA  and TP53 oncogenes as key drivers of breast cancer tumorigenesis. Both TP53 and PIK3CA somatic mutations have been recorded as the top-two recurrent oncogenes in breast cancers [111,122,123,124,125,126], with TP53 dominant in mutations (69%), followed by PIK3CA somatic GOF mutations (29%), indicating their oncogenic driver roles in breast cancer tumorigenesis [127,128]. This evidence concerns the gene PIK3CA and breast cancer.