Paradigm shift from 'Compartment' to 'Zone' in the understanding of organelles

Organelles are intracellular compartments that are delineated by lipid bilayers and play specific roles in regulating various cellular events. Organelle dysfunction contributes to the pathological mechanisms of various diseases. The development and prevalence of super-resolved fluorescence microscopy have enabled the characterization of various functional regions and organellar dynamics by a number of cell biologists. These local functional organelle regions are named 'zones', and three review articles in this issue summarize three different organelle zones, namely, the 'Response zone', 'Communication zone' and 'Sorting zone'. This newest organellar concept may shed light on a novel biological aspect and the elucidation of mechanisms of unresolved diseases.