CERS6 and obesity due to melanocortin 4 receptor deficiency: Ceramide accumulation, particularly in mitochondria and MAMs, contributes to the development of obesity and insulin resistance in mice, which is prevented by the ablation of the C16:0 ceramide producing enzyme ceramide synthase 6 (CerS6) (Raichur et al, 2014; Turpin et al, 2014; Hammerschmidt et al, 2019).