In view of the chronic endoplasmatic reticulum stress conditions with enhanced chaperone activity observed for insulin producing pancreatic β-cells during islet inflammation in (pre) type 1 diabetes as well as during metabolic stress in states of insulin resistance and obesity [20,21], we hypothesized that (prepro-) insulin interacts with chaperones. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.