Transcriptional activator. Plays a role in ventral mesoderm specification and acts together with nog during muscle differentiation. Mediates posterior pattern formation of the embryo, including specification of posterior mesoderm, via activation of the Wnt and Fgf signaling pathways (By similarity). Interacts with ripply2.2/bowline. Associates with tle4 in the presence of ripply2.2/bowline (By similarity).