Overlapping of the risk genes of these three diseases revealed that only eight risk genes were in the intersection, namely, ATXN2, ICOS, CTLA4, BACH2, HLA-DQA1, STAT4, SH2B3, and RNU6-474P, among which ICOS and HLA-DQAI are DEGs in the three autoimmune diseases (Figure S1D). The gene discussed is CTLA4; the disease is autoimmune disease.