SLC30A1 and obesity due to melanocortin 4 receptor deficiency: Although the present study employs fatty tissue samples as a whole—which includes macrophage involvement—our findings support a condition of cytoplasmic zinc deficiency within adipocytes in obesity, as we see downregulation of ZIP14 paralleled by an upregulation of ZNT1, the only SLC30A efflux transporter in the plasma membrane (51).