A recent work on NETs of different grades and primary sites, including pancreas, midgut and lung, analyzed expression characteristics of PD-L1, PD-L2, indoleamine-deoxygenase-1 (IDO-1), tumor-infiltrating T-lymphocytes (TILs), as well as biomarkers of hypoxia and angiogenesis [49]. This evidence concerns the gene CD274 and neoplasm.