We analysed the most studied cancer-associated gene polymorphisms29,30, namely Cytochrome P450 1A1 (CYP1A1) exon 7 (A>G) CYP1A1 2A (T>C), CYP2C19*2 (G>A), GSTT1, GSTM1, GSTP, X-ray repair cross-complementing group 1 (XRCC1) 399 (G>A), 194 (C>T), 280 (A>G), Xeroderma pigmentosum complementation group C (XPC) exon 15 (A>C), XPC exon 9 (C>T) and Xeroderma pigmentosum complementation group D (XPD) (A>C). Here, GSTM1 is linked to cancer.