The proposed effects of mast cells in obesity, however, were inferred from experiments in Kit mutant mast cell-deficient mouse strains KitW/W-v and KitW-sh/W-sh (12, 13, 18), which displayed significantly lower weight gain and an improved obesity-related metabolic and inflammatory phenotype as compared to control mice. Here, KIT is linked to obesity due to melanocortin 4 receptor deficiency.