On May 29, 2019, at the Osaka University Hospital, Japan, the “Organelle Zones” research grant group (see http://organellezone.org/english/ ) organized a 1 day symposium for its own members and four guest speakers, with about 60 attendees. The research group studies three different ways in which regions within organelles carry out functions distinct from other parts of the organelle. Work at this suborganellar level is increasingly recognized as an important aspect of cell biology. The group’s projects are divided into these themes with 9 Principal Investigators and 18 Coinvestigators over 5 years. The symposium followed a similar meeting in 2018 and had four speakers from within the consortium as well as the external speakers. The talks were divided into three sessions, each showcasing one way of subcompartmentalizing organelles into zones.