HRAS and neoplasm: Data obtained from the Cancer Genome Atlas Network (TCGA) show that tobacco-related tumours are characterized by numerous mutations in four groups of genes: those regulating the cell cycle (CDKN2A and CCND1), those determining cell proliferation and survival (TP53, HRAS, PIK3CA, and EGFR), those controlling cell differentiation (NOTCH1), and a gene regulating the Wnt signalling pathway [3,13,14].