Transcription factor. Binds to the consensus DNA sequence 5'-AACAAT-3'. Also binds 5'-CACAAT-3' and 5'-AATAAT-3' but with a lower affinity. Acts partially redundantly with sox7 during cardiogenesis, acting indirectly through nodal-signaling to induce mesodermal, organizer and endodermal tissues, which then interact to initiate cardiogenesis. Also acts as an antagonist of beta-catenin signaling (By similarity). Binds target DNA via the HMG box domain. The 9aaTAD motif is a transactivation domain present in a large number of yeast and animal transcription factors.