In addition, because rs649530917,18 in CHRNB4 and rs80341912,17 in HYKK had been reported to exhibit the strongest association with lung cancer risk in CHRNB4 and HYKK, separately, we also explored the effect of rs6495309 and rs8034191 on whole-genome gene expression level (Supplementary Data 4). The gene discussed is CHRNB4; the disease is lung cancer.