CYP2E1 and cancer: The CYP2E1 C1/C1 genotype shows higher transcriptional activity compared with the CYP2E1 C2/C2 genotype.[34] Therefore, upon exposure, the enzymatic activity of bladder procarcinogens in C2/C2 subjects may compete poorly compared with C1/C1,[35–37] leading to increased cancer susceptibility.