KRAS and neoplasm: Similarly to other epithelial tumours, SCLC is characterized by several chromosomal aberrations, including a great number of chromosomal deletions with recurrent losses at 3p, 5q, 13q and 17p regions, which are actually linked to tumour suppressor genes, as well as copy gains at 1p, 2p, 3q, 5p, 8q and 19p, encoding for well-studied oncogenes, such as MYC and KRAS, both highly correlated to tumorigenesis.