To date, genetic polymorphisms of human CYP1A1 have been widely studied for the susceptibility to various cancers (e.g., cancer of lung, oral, larynx, breast, thyroid, prostate, renal, cervix uteri, gastric, and colon) (Li et al., 2004; Gajecka et al., 2005; Little et al., 2006; Siraj et al., 2008; Wright et al., 2010; Li et al., 2016; Balaji et al., 2012; Agudo et al., 2014; Meng et al., 2015). The gene discussed is CYP1A1; the disease is cancer.