The association between CYP3A4 and VDRTaqI SNPs, and the risk of developing PRCa in BPH patients have been investigated further in this study by determining the CYP3A4*1B and VDR TT genotype frequencies in 400 patients with BPH who have been followed up to 11 years. Here, CYP3A4 is linked to pure red-cell aplasia.