EGFR and lung cancer: The viability assays revealed that lung cancer cells expressing L861Q + G719A showed decreased sensitivity (8- to 58-fold reduction) to EGFR-specific inhibitors, erlotinib and osimertinib, compared with cells expressing L861Q alone, but pan-ERBB inhibitors exerted superior growth-inhibitory effects on cells expressing compound L861Q/G719X mutations (26).