As CTLA4 plays an important role in the downregulation of the immune response, the single-nucleotide polymorphisms (SNPs) of the CTLA4 gene +49 A/G (rs231775) and +6230 G/A (rs3087243) are associated with autoimmune diseases [6, 7] and play an influential role in graft rejection and the long-term clinical outcome of organ transplantation [8–10]. The gene discussed is CTLA4; the disease is autoimmune disease.