CTLA4 and rheumatoid arthritis: Biological agents such as monoclonal antibodies and recombinant proteins that antagonize TNF-α, CD20, CTLA-4 (cytotoxic T-lymphocyte-associated protein 4), IL-1 receptor, and IL-6 receptor as well as therapies based on the blockade of T-cell and B-cell functions have shown efficacy to control physical signs and radiological progression in RA patients [21, 25, 117].