i) Serum RBP4 concentrations decrease in response to hyperinsulinemia, ii) ghrelin abrogates the inhibitory effect of insulin on circulating RBP4 concentrations, and iii) ghrelin as well as GH acutely induces insulin resistance in skeletal muscle without significant changes in circulating RBP4 levels. The gene discussed is RBP4; the disease is Insulin resistance.