It was recently shown that BDNF acts on pancreatic-islet-expressed-TrkB to promote peripheral insulin secretion, thus contributing to normalising hypoglycaemia (87), so it is possible that circulating BDNF enters the pancreas and in this way contributes to maintaining normoglycemia during diving in which glucose consumption is increased due to physical overload and low environmental temperature. The gene discussed is INS; the disease is Hypoglycemia.