As NSCLC, in particular adenocarcinoma, could often be mixed with normal cells, the aim of this study was to estimate the possibility to increase the sensitivity of the detection of K-Ras mutations on an EGFR-targeted naive NSCLC cohort, even in cases of low tumour cellularity and to evaluate its routine clinical usefulness. This evidence concerns the gene KRAS and non-small cell lung carcinoma.