The expression of immune checkpoint (ICP) genes, such as PDCD1 (PD1), CD274 (PDL1), CTLA4, LAG3, and HAVCR2 (TIM3) has been utilized in predicting the response of patients to immune checkpoints therapy in a variety of cancers including PAAD. The gene discussed is CTLA4; the disease is pancreatic adenocarcinoma.