CYP1B1 and cancer: Considering that sequence variants in the noncoding region may also affect the regulation and function of genes and the difficulty of functional characterisation of various CYP1B1 isoforms in vitro, analysing multiple SNPs simultaneously may provide more direct evidence for the relationship between cancer risk and the genetic polymorphisms in CYP1B1. Based on the function of CYP1B1 in activating procarcinogens and transforming oestrogens to genotoxic 4-hydroxyl-CEs, we hypothesise that polymorphisms in CYP1B1 may affect the risk for prostate cancer.