CCL2 and obesity due to melanocortin 4 receptor deficiency: Indeed, hypoxia has been proposed as a key initiator of adipokine dysregulation in obesity [22] by inducing the expression of certain genes in adipocytes and macrophages like TNF-α, IL-1, IL-6, MCP-1, and PAI-1, macrophage migration-inhibition factor (MIF), inducible-nitric oxide synthase (iNOS), and others [41, 46–48].