Definition: CTLA-4 (which stands for "cytotoxic T lymphocyte-associated antigen 4") is a molecule on T-cells (a type of white blood cell) that plays a critical role in regulating natural immune responses. The presence of CTLA-4 suppresses the immune system's response to disease, so blocking its activity has become a target for melanoma and other cancer research. Investigational drugs like ipilimumab are designed to block the activity of CTLA-4, and thereby activate the immune system to fight metastatic melanoma.
Also Known As: cytotoxic T lymphocyte-associated antigen 4
Alternate Spellings: CTLA4
