KRAS and non-small cell lung carcinoma: Considering that KRAS mutant NSCLC may develop primary resistance to EGFR tyrosine kinase inhibitors (EGFR‐TKI) and EGFRT790M mutation causes over 50% of acquired resistance to EGFR‐TKIs, A549 cells with KRAS mutation, and NCI‐H1975 cells with EGFRL858R and EGFRT790M double mutation were used.