CD86 and Autoimmunity: Several stimulatory signals, such as CD28/CD80, CD86, CD27/CD70, CD40/CD40L, ICOS/ICOSL, are involved in the activation and expansion of T cells; on the other hand, inhibitory pathways are similarly important to prevent autoimmunity, such as PD-1/PD-L1 and PD-L2, CTLA-4/CD80 and CD86, A2AR/adenosine, LAG3/Major histocompatibility complex (MHC) class II [8,9].