The recent development of scientific imaging techniques have lead to the identification of various novel organellar functions. Most of these functions are perfomred in limited areas within organelles. These local functional organelle regions are referred to as 'zones'. In mitochondria, there are various types of zones exist, including the apoptosis zone, necrosis zone, mitophagy zone, mitochondrial-derived vesicle budding zone, innate immunity zone, etc. The membrane contact site between mitochondria and the endoplasmic reticulum, which is referred to as MAM, is also considered a zone. This contact site is crucial for various biological events, such as lipid transfer, sterol exchange, Ca2+ transfer, autophagy and the suppression of neurological disorders. Therefore, the elucidation of organelle zones is essential towards a deeper understanding of cell biology.