While SNPs in the phase I and II metabolism genes CYP1A1, GSTM1, GSTT1 and GSTP1 alone did not correlate with pancreatic cancer risk, a significant interaction between smoking and the GSTT1 null genotype was reported in Caucasian pancreatic cancer subjects [18]. This evidence concerns the gene CYP1A1 and familial pancreatic carcinoma.