Transcription factor that is involved in regulation of organogenesis. Seems to be a regulator of SIX1, SIX6 and probably SIX5. Corepression of precursor cell proliferation in myoblasts by SIX1 is switched to coactivation through recruitment of EYA3 to the SIX1-DACH1 complex. Transcriptional activation seems also to involve association of CREBBP. Seems to act as a corepressor of SIX6 in regulating proliferation by directly repressing cyclin-dependent kinase inhibitors, including the p27Kip1 promoter (By similarity). Inhibits TGF-beta signaling through interaction with SMAD4 and NCOR1. Binds to chromatin DNA via its DACHbox-N domain (By similarity). Interacts with SIX1, SIX6 and EYA3. Interacts with NCOR1 and HDAC3 through its N-terminus. Interacts with SIN3A through its C-terminus (By similarity). Interacts with SMAD3 and SMAD4. Additional isoforms seem to exist. Widely expressed. Isoform 2 is found in brain, heart, kidney, liver, leukocytes and spleen. Isoform 3 is found in liver and heart. Isoform 4 is found in spleen. The DACHbox-N/DD1 domain forms a structure containing a DNA binding motif similar to that of the forkhead/winged helix domain. Major. Belongs to the DACH/dachshund family. Truncated N-terminus.