NSCLC samples were examined following either macro or Laser micro dissection for the presence of driver mutations in EGFR (n = 956), KRAS (n = 720), BRAF (n = 472), PIK3CA (n = 184) genes, MET gene copy number amplification (n = 170), ALK gene rearrangement (n = 107) in an effort to define the occurrence of molecular alterations in NSCLC and their possible contribution to clinical decision making. This evidence concerns the gene KRAS and non-small cell lung carcinoma.