Indeed, measurements of plasma visfatin levels in human beings have yielded conflicting results, with raised levels being reported in obese children [22], diabetic patients [23, 24], patients after weight loss mediated by gastroplastic surgery [25] and patients being treated with thiazolidinedione and rosiglitazone [26], whilst other studies have reported reduced levels with gestational diabetes [27], exercise in patients with type 1 diabetes [28], massive weight loss [29] and obesity [30]. The gene discussed is NAMPT; the disease is obesity due to melanocortin 4 receptor deficiency.