Furthermore, Olivieri et al., [67] Figaro Gattá et al. [68], Tanimoto et al. [69], and Singh et al. [23] reported that the Brazilian, the Japanese, and the North Indian patients carrying CYP1A1 (*1A/*2A) genotype presented an increased HNSCC risk. This evidence concerns the gene CYP1A1 and head and neck squamous cell carcinoma.