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).
A measurement in which the number of individuals in a study population displaying one or more tumors of the pituitary gland at a point in time or developing such growths within a determined period of time, are compared to the total number of individuals in the study population. Often expressed as a percentage but could be expressed as a ratio. A tumor is an abnormal growth of tissue resulting from uncontrolled, progressive multiplication of cells and serving no physiological function.