IMMP1L (inner mitochondrial membrane peptidase subunit 1) is a mitochondrial endopeptidase that catalyzes the removal of transit peptides from proteins destined for the mitochondrial intermembrane space, including processing of the nuclear-encoded protein DIABLO. The enzyme functions as part of the mitochondrial inner membrane peptidase complex. Regarding disease relevance, IMMP1L has emerged as a candidate gene in metabolic and developmental disorders through multiple genetic studies. An obesity-associated SNP near IMMP1L associates with DNA methylation changes at its proximal promoter, suggesting regulation through epigenetic mechanisms that may influence body weight 1. More significantly, IMMP1L deletions downstream of PAX6 have been identified in families with aniridia and diabetes mellitus. Functional studies demonstrated that Immp1l knockdown in pancreatic β-cells, particularly when combined with Pax6 reduction, impairs glucose-stimulated insulin secretion, indicating a role in glucose homeostasis 2. IMMP1L is consistently found within the PAX6 downstream regulatory region (DRR) in reported cases of aniridia-associated deletions 34, though phenotypic heterogeneity exists, suggesting IMMP1L may contribute to but is not solely responsible for the ocular phenotype. Clinically, genetic screening for IMMP1L deletions may be warranted in aniridia patients with intact PAX6 coding sequences, and assessment for glucose intolerance in deletion carriers could enable early diabetes intervention.