Enables protein homodimerization activity. Predicted to be involved in several processes, including enzyme linked receptor protein signaling pathway; reduction of food intake in response to dietary excess; and regulation of signal transduction. Predicted to act upstream of or within positive regulation of myoblast fusion. Located in extracellular region. Orthologous to human GDF15 (growth differentiation factor 15). [provided by Alliance of Genome Resources, Apr 2022]