ERG and prostate cancer: Our previous studies characterize that ERRα can perform multiple oncogenic functions in prostate cancer, including promotion of hypoxic growth via its direct interaction with HIF-1α and enhancement of HIF-1 signaling [22], transactivation of oncogenic TMPRSS2:ERG fusion gene and formation of a transcriptional reciprocal loop with ERG [23] and regulation of intratumoral androgen biosynthesis in castration-resistant prostate cancer (CRPC) via its transcriptional control of multiple steroidogenic enzymes [24].