mCRC:KRAS, NRAS, BRAF, AKT1 and PIK3CA mutationsEGFR ectodomain mutations S468R, G465R, G441R/E and K443TMET, KRAS, FGFR1 and ERBB2 amplificationSCCHN:EGFR ectodomain mutations G33S, N56K (patient-derived HNSCC cells) and G465RERBB3 activation and ERBB2/ERBB3 dimerization (PDX models). The gene discussed is EGFR; the disease is head and neck squamous cell carcinoma.