These experiments were followed by the first descriptions of Tregs by Sakaguchi et al. (1995, 1996) as a circulating subset of CD4+ T cells expressing high levels of CD25 (the IL-2 receptor α-chain), which could prevent the development of multi-organ autoimmune diseases (thyroiditis, gastritis, insulitis, sialoadenitis, adrenalitis, oophoritis, glomerulonephritis, and polyarthritis) and/or rodent graft-versus-host disease (GVHD)-like wasting disease in thymectomized mice, by adoptive transfer (Suri-Payer et al., 1998). Here, CD4 is linked to autoimmune disease.