Interestingly, we also found a small population of TRM enriched in primary PDA expressing both co-stimulatory, ICOS and 41-BB, and co-inhibitory, PD-1, TIGIT, Tim-3 and BTLA, immune checkpoint receptors, as well as CD95 (Fas) that leads to apoptotic cell death (C9, Supplementary Figures 8I, J). This evidence concerns the gene ICOS and Patent ductus arteriosus.