CD28 and inflammatory bowel disease: For instance, CD28- CD8+, CD122+ CD8+, C39+ CD26- CD8+, LAG3+ Foxp3+ CTLA4+ CD8+, CD103+ CD8+ and IL10+ CCR7+ CD45RO+ CD8+ constitute regulatory CD8+ T subsets that exhibited suppressive abilities in transplantation, autoimmunity and IBD (42, 44, 71).