Common genetic alterations in prostate cancer include HPCI mutation [39], losses or down-regulation of the tumor suppressor protein NKX3.1 [40, 41], loss or mutation of PTEN [42, 43], TMPRSS2-AR or ERG1-AR gene fusion [44–46], and AR upregulation [47]. The gene discussed is TMPRSS2; the disease is prostate cancer.