Abnormal transmembrane signal pathways, including prosurvival pathways (PI3K/Akt, NF-κB, MAPK, STAT3, Wnt/β-catenin) and proapoptosis pathways (p53, endoplasmic reticulum stress) in NPC cells, have been proved to be associated with the development, progression, and prognosis of NPC by influencing biological processes such as cell cycle, apoptosis, and DNA repair. The gene discussed is PIK3CA; the disease is nasopharyngeal carcinoma.