Among the smokers, individuals with the CYP1A1 Vt allele and Val allele showed a significantly increased risk of RCC (Vt allele: OR = 3.37, 95%CI = 2.24–5.06; Val allele: OR = 2.07, 95%CI = 1.34–3.19). The gene discussed is CYP1A1; the disease is renal cell adenocarcinoma.