Abstract Background Stem cells and stem cell lines are widely used in biomedical research. The Cell Ontology (CL) and Cell Line Ontology (CLO) are two community-based OBO Foundry ontologies in the domains of in vivo cells and in vitro cell line cells. respectively. Results To support standardized stem cell investigations. https://unitedssports.shop/product-category/bike-parts-brakes-levers/