MMP12 and obesity due to melanocortin 4 receptor deficiency: We have detected new molecular aspects of obesity-derived effects on placentas, where the glucocorticoid receptor signalling pathway and dysregulation of several genes including CCL2, FSTL3, IGFBP1, MMP12, PRG2, PRL, QSOX1, SERPINE2 and TAC3 might have important roles.