An endogenous gastrointestinal hormone; activates GHS-R by 41% when used at 10 μM (IC50 = >10,000 nM; EC50 = >10,000 nM for increasing calcium accumulation); inhibits cell proliferation in estrogen-dependent MCF-7 breast cancer cells (EC50 = 0.81 μM); induces proliferation of a somatotroph pituitary tumor cell line