Enables co-SMAD binding activity. Involved in cellular response to growth factor stimulus; negative regulation of gene expression; and response to xenobiotic stimulus. Located in nucleus. Biomarker of muscular atrophy. Human ortholog(s) of this gene implicated in holoprosencephaly and holoprosencephaly 4. Orthologous to human TGIF1 (TGFB induced factor homeobox 1). [provided by Alliance of Genome Resources, Apr 2022]