CD8A and type 1 diabetes mellitus: A CD8+ T cell exhaustion phenotype has been associated not only with slower progression to complete loss of insulin secretion following diagnosis (31), but also with response to teplizumab (anti-CD3 monoclonal antibody) in new-onset T1D (37, 38) and at-risk individuals (39), as well as alefacept (lymphocyte function–associated antigen 3–IgG fusion protein) in new-onset individuals (40).