PDCD1 and neoplasm: A study using metabolomics for PDAC under anti-PD-1 and anti-CTLA-4 conditions demonstrated increased sensitivity of ICIs by IL17 inhibitor resulting in prevention of cytotoxic CD8 T-cell exclusion from tumors and suggested that tumor lactate may serve as a promising early biomarker for efficacy of IL17/PD-1 combination [93].