MLKL and obesity due to melanocortin 4 receptor deficiency: As RIPK3 can regulate the death- and inflammation-inducing activity of both caspase-8 and MLKL in disease-causing macrophages (Vince et al, 2012; Lawlor et al, 2015), direct comparisons of mutant animals in the same obesity and MAFLD model are required to define their pathological roles and divergent activities.