CCDC51 (also called MITOK) is a mitochondrial inner membrane protein that functions as the pore-forming subunit of the ATP-gated potassium channel (mitoK(ATP)) 1. Working together with the ATP-binding subunit ABCB8, CCDC51 mediates ATP-dependent K+ currents across the mitochondrial inner membrane, with increased intracellular ATP closing the channel and decreased ATP enhancing K+ uptake into the mitochondrial matrix 1. This ATP-sensing mechanism contributes to homeostatic control of cellular metabolism and mitochondrial matrix volume regulation under stress conditions 1. Beyond its ion channel function, CCDC51 plays a direct role in mitochondrial dynamics. CCDC51 is spatially and temporally localized to a subset of mitochondrial fission events and is functionally conserved with yeast Mdm33 23. CCDC51 depletion reduces mitochondrial fission rates, while overexpression promotes mitochondrial fragmentation through association with Drp1, indicating it acts as a positive effector of fission 3. Clinically, CCDC51 mutations have been associated with non-syndromic rod-cone dystrophy, with a homozygous frameshift variant identified in a consanguineous family patient 4. CCDC51 expression also associates with stemness features in lung squamous cell carcinoma and KATP channel expression changes in glioblastoma 56, suggesting roles in cancer biology and metabolic heterogeneity.