✓a selective PI3K p110α inhibitor (IC50 = 5 nM) [221]✓reduces p-RPS6 (S240/244) in HRAS wild-type HNSCC cell lines but not a HRASG12V mutant cell line due to the ERK/TSC2 signaling [113]. Here, PIK3CD is linked to head and neck squamous cell carcinoma.