SRD5A2 and posterior cortical atrophy: To this end, we investigated if homozygosis in the risk-bearing alleles (i.e. the f allele of the VDR FokI locus, and the (TA) 9 allele of SRD5A2 gene) or the protective alleles (i.e. the F allele of the VDR FokI locus, and the (TA) 0 allele of SRD5A2 gene) are unevenly distributed among the subjects with PCa and the controls.