blood T lymphocyte count blood natural killer T cell count 2012-09-04T06:28:02Z CMO:0001086 NKT cell count The number of natural killer T (NKT) cells in a specified volume of blood. NKT cells are a specialized population of T cells that express both a semi-invariant T cell receptor (TCR alpha beta) and surface antigens typically associated with natural killer cells. This term is not to be used for natural killer (NK) cells. clinical_measurement_ontology jsmith