CYP1A1 and prostate cancer: While CYP1A1 expression was weak or not detected in most of the normal prostate (0.79 ± 0.11) and BPH (0.57 ± 0.07) tissues, the majority of prostate cancer samples showed much higher CYP1A1 immunoreactivity with an average staining score of 1.82 ± 0.08 (P < 0.001, Figure 1C).