All 4 heart explants from chronically infected subjects with diffuse severe myocarditis showed a variable number of CTLA-4+ cells (average percentage of CTLA-4+ cells/total infiltrating cells counted = 7,6±6; range = 1–23% in 10 representative fields per patient) [Figure 7A and 7B]. The gene discussed is CTLA4; the disease is myocarditis.