T lymphocyte, cytotoxic

T lymphocyte, cytotoxic A cell that expresses the CD8 transmembrane glycoprotein and is antigen specific. Abbreviated CTL. CTLs are able to search out and kill specific types of infected or abnormal cells. When they find cells carrying the peptide they are looking for, they induce those cells to secrete proteins that attract nearby macrophages (specialized white blood cells). These macrophages then surround and destroy the targeted cells. CTLs are particularly important in the immune response to viruses and cancer. Also known as TC cell. See also CD8; T cell; T-suppressor cell.