Consistently, lung cancer patients with the rs6495309C genotypes had poor survival, because smoking is always associated with a decreased survival of lung cancer [27], and CHRNA3 functions to promote chemotherapy resistance through the Akt-dependent proliferation and the NF-kappaB-dependent survival pathways under the stimulation of NNK [36], [42]–[44]. Here, CHRNA3 is linked to lung cancer.