Predicted to enable hormone activity. Acts upstream of or within glucose homeostasis; regulation of primary metabolic process; and response to starvation. Predicted to be located in extracellular region. Is expressed in several structures, including digestive system; gill; heart; hypophysis; and pleuroperitoneal region. Used to study type 2 diabetes mellitus. Human ortholog(s) of this gene implicated in several diseases, including alcohol dependence; congenital leptin deficiency; liver disease (multiple); lung disease (multiple); and type 2 diabetes mellitus. Orthologous to human LEP (leptin).