UGT2B17 and Familial prostate cancer: UGT2B17, along with UGT2B15 and UGT2B28, is a major enzyme involved in steroid inactivation in both normal and prostatic cancer cells (Fig. 1).18–20 UGT2B17 shares 94% amino acid sequence identity with UGT2B1518 and 76% with UGT2B28.20 It was previously documented that UGT2B17 mRNA expression is associated with PCa disease stages, being overexpressed in castration-resistant metastasis.21 More recently, the complexity of the UGT2B17 transcriptome was exposed with at least ten alternative mRNA isoforms,22 but it remains unclear which transcripts are linked to disease stages.