The immune response is naturally kept in check by immune checkpoint molecules [cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1) and programmed death ligand 1 (PD-L1)] in order to prevent over-activation of the immune response resulting in autoimmune disease. This evidence concerns the gene CTLA4 and autoimmune disease.