Moreover, the highest quartile of PDA TREG signature scorers exhibited significantly greater expression of cd3e, cd8a, gzmb, and prf1 than the PDA patients of the lower quartile (Fig. 6i), suggesting that intra-tumoral TREGS are accompanied by concomitant infiltrates of cytotoxic T cells in PDA patients. This evidence concerns the gene PRF1 and Patent ductus arteriosus.