To consider the different human EGFR mutation profiles observed in NSCLC patients, four tumor cell lines with different EGFR mutations were used: (i) A549 cells that have KRAS G12S mutation and no EGFR mutation, (ii) PC9 cells that have exon 19 deletion, (iii) H1975 cells that have T790M and L858R mutations, and (iv) HCC827 cells that have exon 19 deletion. The gene discussed is KRAS; the disease is neoplasm.