Importance of landscape exploration and progress in molecular therapies and precision medicine for pancreatic ductal adenocarcinoma

Figure 5 Schematic illustration of the different cell types in the tumor microenvironment. Some of these cell types can be targeted to turn “cold” pancreatic tumors into “hot” pancreatic tumor. PD-L1: Programmed-death ligand 1; PD-1: Programmed cell death protein 1; CTL-4: Cytotoxic T lymphocyte 4; CAR-T: Chimeric antigen receptor-engineered T; TCR: T cell receptor; CTLA-4: Cytotoxic T lymphocyte associated antigen 4; CAF: Cancer-associated fibroblast; Treg: Regulatory T; NK: Natural killer.