PDCD1 and pancreatic neoplasm: Specifically, anti-TIGIT has been recently proposed as an alternative immunotherapy to anti PD-1 in colorectal, lung and pancreatic cancers [50], anti-CD73 which is the ligand for CD39 has also successfully passed a phase 1 in advanced cancers [51], and anti-ICOS has shown specific targeting of Tregs in mouse models [52].