Stimulated by growth factors and other proliferative signals, proliferation-related signaling pathways, such as the RAS, the phosphoinositide 3-kinase (PI3K)-protein kinase B (AKT)-mammalian target of rapamycin (mTOR) pathway, and the RAF-mitogen-activated protein kinase (MAPK) kinase (MEK)-extracellular signal-related kinase (ERK) pathway, are activated in tumor cells, which subsequently regulate tumor cell proliferation, migration and invasion, gene transcription, cellular metabolic reprogramming, and tumor microenvironment (TME) remodeling.301–303. The gene discussed is PIK3CA; the disease is neoplasm.