PIK3CA and breast cancer: In a genetic evaluation of in vitro breast cancer, MCF-7 cells were incubated with 0 to 20 mM exogenous lactate and analyzed for the expression of proto-oncogenes (i.e., NRAS, MYC, and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha PIK3CA), proliferative genes (i.e., ATM, CCND1, CDK4, CDK1A, CDK2b, AKT1, and MIF), tumor suppressors (i.e., BRCA1 and BRCA2), and transcription factors (i.e., HIF1A and E2F1) [130].