Visceral adipose tissue derived serine protease inhibitor (vaspin), also known as SERPINA12, is a member of the serpin family (4), that was first identified in visceral (omental) AT of the Otsuka Long-Evans Tokushima fatty (OLETF) rat, an animal model of obesity and T2D (5). Here, SERPINA12 is linked to obesity due to melanocortin 4 receptor deficiency.