PIK3CA and nasopharyngeal carcinoma: The 50% inhibitory concentration (IC50) for PQR309 in PIK3CA mutant NPC cell lines ranged from 0.008617 μM to 0.6002 μM, while the IC50 values in HK-1 and C666-1 cells with wild-type PIK3CA were 0.01342 and 0.01495 μM, respectively.