ENTPD1 and Sepsis: In the same way, the co-stimulatory molecules PD-1 and exhaustion markers CD39 frequency (respectively, CD3+CD4+CD25+CD127-FOXP3+ cells and CD3+CD4+CD25+CD127-FOXP3+PD-1+) (Figures 3C, E), showed an increase in neonates developing sepsis compared to healthy newborn and those with presumed sepsis.