The Epilepsy Ontology (BioPortal ID: EpSO) is an application ontology developed to support epilepsy research, patient care, and health system management.The updated version of the Epilepsy Ontology adds Dravet Syndrome (DS) related terms covering both model systems and patients with DS. This version expands on the prior version of the ontology, which focused on neuropathology terms, including immunohistochemistry, microscopy, and anatomical description, related to epilepsy.This work has been funded in part by the Dravet Syndrome Foundation (DSF), International League Against Epilepsy (ILAE), and the US National Institutes of Health (NIH). Some of the funding agencies retain intellectual ownership of the ontology, together with the Case Western Reserve University and other collaborating institutions.Contributors: Satya S. Sahoo, Jeffrey Buchhalter, Samden D. Lhatoo, Katja Kobow, Deepak K. Gupta, Alireza Bozorgi, Aman Dabir, Bilal Gonen, Hans O. Luders, Kenneth Loparo, Veronica HoodContact: satya.sahoo@case.edu