In many cases, endocrine dysfunction (hypothyroidism, hyperthyroidism, adrenal insufficiency, hypophysitis) can be adequately treated on a symptomatic basis except in patients with diabetes, where such treatment could trigger a life-threatening situation as T1DM (type 1 diabetes mellitus) with ketoacidosis demands a strict work-up and insulin substitution. This evidence concerns the gene INS and diabetes mellitus.