NRG4 and Insulin resistance: However, as we have shown in our manuscript, peptides potentially involved in induction of insulin resistance may be synthesized in other organs, for example, in the pancreas (e.g., preptin), hypothalamus (e.g., nesfatin), skeletal muscles (e.g., myonectin), intestine (e.g., xenin), immune cells (e.g., lipocalin-2) and, in terms of adipose tissue, it can occur either in the visceral one (e.g., omentin, gremlin-1) or brown adipose tissue (e.g., neuregulin-4).