NFE2L2 and adenocarcinoma: While the allele frequency of SNP c.–617C>A in the NRF2 gene was estimated to be 25.2%, non-smoking females harboring homozygous alleles (–617A/A) had a markedly higher incidence of adenocarcinoma (Table 4, Table 5), as compared with non-smoking males harboring the same genotype.