Although the aforementioned M and C cancer classes are at the top of a global genomic pattern analysis across various cancer types, there appear similar M and C classes in invasive ductal carcinoma, in which M and C represent low and high grade IDC characterized by PIK3CA, GATA3 or other gene mutations and TP53 mutation, MYC amplification, or other gene amplifications, respectively. The gene discussed is PIK3CA; the disease is invasive ductal breast carcinoma.