ETS1 and posterior cortical atrophy: Taken together, our findings that ERG is specifically associated with ETS-2 and ETV-4, but not with ETS-1, in PC3 cell nuclear extracts and PCa tissues strongly support the notion that ERG is part of a complex integrated transcriptional network that involves other ETS factors, such as ETS-2 and ETV-4, which are likely to cooperate or influence the activity of ERG in PCa.