The (gamma)-tocopherol metabolite, (gamma)-CEHC, is produced in the liver by the action of CYP450 enzymes and excreted in urine at levels that exceed all other tocopherol metabolites. In plasma, (gamma)-tocopherol has the ability to trap NO radicals, and both (gamma)-tocopherol and (gamma)-CEHC inhibit COX activity in macrophages and epithelial cells. Thus, the concentration of (gamma)-tocopherol in plasma could be indicative of events related to cardiovascular disease and cancer. Cayman's (gamma)-CEHC EIA is a competitive assay that can be used for efficient quantification of (gamma)-CEHC in plasma and serum.