INS and obesity due to melanocortin 4 receptor deficiency: Obesity and high fat feeding mimic the effects of long-term incubation of islets with FFA on insulin secretion and Ca2+-channel distribution (Collins et al., 2010) which correlate with an increased amount of fat within the islets (Hoppa et al., 2009) and the surrounding exocrine pancreas (Pinnick et al., 2008).