CTLA4 and familial pancreatic carcinoma: In a pancreatic cancer mouse model, pharmacological macrophage depletion enhances tumor reduction induced by antibodies against T cell inhibitory receptors cytotoxic T-lymphocyte- associated antigen 4 (CTLA4) and programmed cell death protein 1 (PD1) that augment tumoricidal CD8 + T cell responses [48].