Attractin (Atrn, also called mahogany, 0.49-fold) is a low-affinity receptor for Agouti protein (He et al., 2001), its membrane-bound isoform is a receptor involved in controlling obesity and its secreted isoform is involved in the initial immune cell clustering during inflammatory responses by regulating the chemotactic activity of chemokines (Duke-Cohan et al., 1998). Here, ATRN is linked to obesity due to melanocortin 4 receptor deficiency.