This was done by comparing the effect of EGF administration, NEU3 overexpression and treatment with a specific EGFR-targeted therapy, gefitinib, in a healthy lung mucosa cell line (HSAEC1) and in two representative NSCLC cell lines, one of which sensitive (HCC4006, carrying a classical deletion in EGFR exon 19) and one resistant (H1734, with a EGFR wild-type gene status and carrying a KRAS exon 2 mutation) to gefitinib. The gene discussed is KRAS; the disease is non-small cell lung carcinoma.