Enables epidermal growth factor receptor binding activity and growth factor activity. Involved in several processes, including positive regulation of fibroblast proliferation; positive regulation of mitotic nuclear division; and positive regulation of urine volume. Predicted to be integral component of membrane. Predicted to be active in extracellular space. Biomarker of otitis media. Human ortholog(s) of this gene implicated in type 1 diabetes mellitus and type 2 diabetes mellitus. Orthologous to human BTC (betacellulin). [provided by Alliance of Genome Resources, Apr 2022]