MIPEP encodes mitochondrial intermediate peptidase (MIP), a metalloendopeptidase localized to the mitochondrial matrix that processes nuclear-encoded mitochondrial proteins 1. MIP removes N-terminal mitochondrial targeting signals and cleaves specific octapeptides from imported protein precursors, particularly oxidative phosphorylation (OXPHOS) subunits and mitochondrial genetic apparatus components 1. This post-import proteolytic maturation is essential for proper mitochondrial protein folding and OXPHOS complex assembly 2. MIPEP is differentially expressed across tissues with highest levels in heart, skeletal muscle, and pancreas—organs frequently affected in OXPHOS disorders 1. Loss of MIPEP function impairs mitochondrial proteostasis, reducing OXPHOS abundance and activity 2. Adipocyte-specific MIPEP deficiency suppresses mitochondrial biogenesis genes, causes lipoatrophy and brown adipose tissue whitening, and triggers systemic metabolic dysfunction and inflammation 3. Clinically, MIPEP variants cause combined oxidative phosphorylation deficiency presenting with developmental delay, hypotonia, and optic neuropathy 2. Additionally, MIPEP genetic variants are associated with high myopia susceptibility in genome-wide association studies 45, though the mechanistic link to refractive error remains unclear.