Enables identical protein binding activity. Involved in several processes, including cellular response to BMP stimulus; positive regulation of brown fat cell differentiation; and positive regulation of white fat cell proliferation. Located in extracellular region. Is expressed in central nervous system; head mesenchyme; hindlimb mesenchyme; and jaw bone. Orthologous to human VSTM2A (V-set and transmembrane domain containing 2A). [provided by Alliance of Genome Resources, Apr 2022]