IRDiRC has recently accepted a new Recognized Resource, the Cellosaurus, a knowledge resource on cell lines aiming to describe all cell lines used in biomedical research. The Cellosaurus provides information for about 130,000 cell lines and 25% of these cell lines are established from rare disease patients. For each cell line the Cellosaurus provides a wealth of information, cross-references and literature citations. The Cellosaurus is available on the ExPASy server (https://web.expasy.org/cellosaurus/) and can be downloaded in a variety of formats.