CD274 and neoplasm: This model avoids involvement of murine stromal cells that compromise many in vivo model systems.44 Previous studies characterized lymphocytes in ascites (tumour-associated lymphocytes, TALs) to be more similar to tumor (TILs)45 than blood in displaying exhaustion markers (LAG-3, PD-1 and TIM-3).46 We observed significant activation of tumor-associated T cells with both PD-L1 BiTEs when added as free protein or expressed via an oncolytic viral vector (figures 2B and 7A).