 Because CD3 is required for T cell activation, drugs (often monoclonal antibodies) that target it are being investigated as immunosuppressant therapies (e.g., otelixizumab) for type 1 diabetes and other autoimmune diseases.New anticancer drug treatments are being developed based upon the CD3 (cluster of differentiation 3) T cell co-receptor, with molecules being designed for altering the co-stimulatory signal to help get the T-cell to recognize the cancer cell and become fully activated.Cancers that possess the B7-H3 immunoregulatory checkpoint receptor on the tumor cell have been one such target in clinical trials.