CHRNA5 and lung cancer: One of these susceptibility loci, rs16969968, a non-synonymous variant polymorphism located in the exon five of CHRNA5 15q25 resulting in a change in amino acid at residue 398th of CHRNA5 from Asp to Asn (Hung et al., 2008; Zhou et al., 2020), has been identified by GWAS as a risk locus for lung cancer (Weiss et al., 2008).