- Expression in CD31+ HEV in peritumoral stroma: sentinel LN and metastatic tissue associated with reduced CD8+T-cells and increased FoxP3+Tregs (85) - Expression in sentinel LN associated with enhanced IDO expression in peripheral blood (86) - Expression associated with microsatellite instability in CRC (87) - Expression associated with responsiveness to anti-PD-1 (88, 89) - Drives tumor dormancy through Trp depletion-induced TSLP expression/secretion (90) - Expression in LECs impairs CD4+T-cell proliferation (91). The gene discussed is PDCD1; the disease is colorectal carcinoma.