HPGDS and lung cancer: Recently, various gene polymorphisms contributing to lung cancer risk have been discovered, such as DNA repair genes family (XRCC1, hOGG1, XPD, XPA, XRCC3) [2], [3], [4], [5], [6], cytochrome P450 (CYP450) [7], glutathione S-transferases family (GSTs) [8], and MicroRNAs (miRNAs) [9], [10], [11].