The UC10-4F10-11 monoclonal antibody specifically reacts with the mouse Cytotoxic T-Lymphocyte Antigen-4 (CTLA-4), also known as CD152. It is a protein with a structure similar to CD28 regarding the genomic organization, amino acid sequence, and structure. CTLA-4 is expressed on activated T cells and CD25+/CD4+ Treg lymphocytes and binds the members of the B7 family, B7-1 (CD80) and B7-2 (CD86), with higher affinity than CD28. CD28 seems to provide opposing signal to T lymphocytes, while CD152 inhibits the T lymphocytes progression to an activated state and their proliferation, CD28 is a costimulator.

The mouse UC10 -4F10-11 monoclonal antibody does not cross-react with the rat leukocytes.