PPIF and obesity due to melanocortin 4 receptor deficiency: Notably, leucine aminopeptidase III (Lap3) and peptidylprolyl isomerase F (Ppif, encodes Cyclophilin D, CypD), previously characterized as mitochondrial matrix proteins whose localization is facilitated by MTCH2, functioning as a insertase[20]‐have been implicated in fat metabolism and obesity,[21, 22, 23] further supporting the MTCH2's critical role in regulating energy homeostasis.