The Clinical Measurement Ontology (CMO), Measurement Methods Ontology (MMO), and Experimental Condition Ontology (XCO) are currently being developed at the Rat Genome Database. For more information about these vocabularies please see Shimoyama et al. Three ontologies to define phenotype measurement data. Front Genet. 2012;3:87. Epub 2012 May 28 or contact us (http://rgd.mcw.edu/contact/index.shtml).
The amount in a specified sample of serum of rheumatoid factor that is expressed as an immunoglobulin G (IgG) molecule. Rheumatoid factor (RF) is an autoantibody against the Fc portion of IgG found in rheumatoid arthritis and some other autoimmune diseases. RF and IgG join to form immune complexes that contribute to the disease process.