Wang et al. screened common variants in 5′ flanking and 3′ untranslated regions of the adenosine triphosphate-binding cassette B1 (ABCB1) and ABCC1 candidate transporter genes which are the genetic components in the metabolism and disposition of NNK in Chinese population, and examined the association with lung cancer [38]. This evidence concerns the gene ABCB1 and lung cancer.