The behaviour of MICOS-MIB and OXPHOS complexes and the effects on cristae number are consistent with the self-reinforcing role that these components play in formation and stabilization of cristae.37 We note that while cells lacking NPC1 also accumulate FTH1, the corresponding phenotypes and in particular the mitochondrial alterations seen in NPC2−/− cells appear more pronounced, despite only 5% of NPC patients carry mutations in the NPC2 gene.44 This phenotype held also true in stem-cell derived iNeurons. Here, FTH1 is linked to nasopharyngeal carcinoma.