ARMC12 (Armadillo Repeat Containing 12) is a protein localized to the outer mitochondrial membrane and belongs to the protein family containing Armadillo repeat sequences. Its primary function is to act as a positive regulator of mitochondrial fission. Research indicates that ARMC12 interacts with core proteins involved in mitochondrial fission, such as the dynamin-related protein DRP1 and its receptor MFF, facilitating the proper assembly and localization of the mitochondrial fission complex on the mitochondrial surface, thereby precisely regulating the fission process. Mitochondrial fission is crucial for maintaining mitochondrial network homeostasis, energy metabolism, apoptosis, and autophagy. Consequently, dysfunction of ARMC12 is believed to be potentially associated with diseases related to abnormal mitochondrial morphology, such as neurodegenerative diseases, metabolic disorders, and cancer, making it an important subject of study in the field of mitochondrial dynamics.