Ets proteins constitute a family of conserved sequence-specific DNA-binding proteins and function as transcription factors with roles in differentiation, lymphoid cell development, invasiveness and angiogenesis. A novel ETS1 interacting protein designated as ETS1-associated protein II (EAPII) interacts with ETS1 and other Ets proteins (ETS2 and FLI1) and is a novel ETS1 modulator.