Enables collagen binding activity. Involved in several processes, including circulatory system development; negative regulation of adaptive immune response based on somatic recombination of immune receptors built from immunoglobulin superfamily domains; and negative regulation of protein phosphorylation. Acts upstream of or within several processes, including cellular response to leukemia inhibitory factor; negative regulation of BMP signaling pathway; and transforming growth factor beta receptor signaling pathway. Located in nucleus. Part of protein-containing complex. Is expressed in several structures, including cardiovascular system; central nervous system; early conceptus; genitourinary system; and inner ear. Human ortholog(s) of this gene implicated in colorectal cancer and pancreatic adenocarcinoma. Orthologous to human SMAD7 (SMAD family member 7). [provided by Alliance of Genome Resources, Apr 2022]