In Latin America, CTLA4 genetic variants have only been correlated with the development of obesity in northeastern Brazil,23 type 1 diabetes mellitus in Chile,24 FVIII inhibitor development in hemophilia A (HA) patients from Argentina,25 diffuse cutaneous leishmaniasis in Venezuela, 26 and hepatitis C virus27 and rheumatoid arthritis in Mexico.28 The gene discussed is CTLA4; the disease is rheumatoid arthritis.