KRAS and non-small cell lung carcinoma: Then, in a second part, we focused on cell cycle genes that were found to be differentially involved between groups and screened a large series of 98 NSCLC for genetic alterations at CCND1, CCNE1, CDKN2A and RB1. Alterations were studied according to other known mutations (EGFR, ERBB2, BRAF, KRAS, TP53 and STK11).