In cardiac tissue, before infection, the frequencies of CD39+ and CD73+ CD4+ T cells were similar, with relatively low coexpression levels (36.3% ± 11.6% for CD39+, 29.6% ± 8.2% for CD73+, and 10.8% ± 1.6% for CD39+CD73+). This evidence concerns the gene ENTPD1 and infection.