However, it is worth noting that the mechanism by which CTLA-4 regulates the immunity of Treg cells, B cells, NK cells, DC, and macrophages needs to be further studied, as well as the effects of this molecule on endothelial, epithelial, and fibroblast immunoregulation, and its roles in the treatment of various autoimmune diseases. Here, CTLA4 is linked to autoimmune disease.