HOXB13 Recently, a rare, recurrent mutation (G84E) in HOXB13, in the 17q21-12 region was reported to be associated with prostate cancer risk. The homeobox transcription factor gene is important in prostate development. The HOXB13 G84E mutation is found in up to 5% of PCa families, mainly in Northern Europe. Another group undertook a systematic literature review of the Germline Homeobox B13 G84E mutation studies in European Descendants. A meta-analysis of 24213 cases of PCa and 73631 controls was conducted and confirmed that HOXB13 G84E mutation is associated with an increased prostate cancer risk with an Odds ratio of 4.07 (95%CI:3.05-5.45). A subgroup analysis based on ethnic origin revealed that the Odds ratio was highest for the Western Europeans (OR=8.66) and lowest for Northern Europeans (OR=3.63). The G84E mutation was associated with early onset PCa with an Odds Ratio of 10.11 for early onset PCa and 3.63 for late onset PCa. When assessing the aggressiveness of the disease, the G84E mutation appeared not to predict a more aggressive presentation. While further studies are needed to define the clinical utility of these observations, it has been suggested that this variant may also be associated with features of more undifferentiated tumours and therefore may be associated with more aggressive disease.