HPRT1 and neoplasm: In vitro data coming from bronchial epithelial cells exposed to high dose of alpha radiation (238Pu), found significant increased mutations in the TP53 tumor suppression gene, as well as in the locus of the hypoxanthine-guanine phosphoribosyl transferase (HPRT), responsible for the transcription of an enzyme that plays a central role in the generation of purine nucleotides through the purine salvage pathway [44,49].