TMPRSS2 and Familial prostate cancer: The TMPRSS2:ERG gene fusion, which is recognized as one of the most common gene fusions found in prostate cancer patients, was identified in 15 of 44 patients (34%) (Wang et al. 2017), slightly lower than a previously reported estimate of 42.6% in metastatic castrate resistant-prostate cancers (van Dessel et al. 2019).