A possible mechanism is that irinotecan enhances T cell activation caused by anti-PD-L1 therapy possibly by reducing the number of Tregs and by augmenting expression of MHC class I on tumor cells, and at the same time, the anti-PD-L1 antibodies can block the irinotecan-induced PD-L1 in tumors and lymph nodes. Here, CD274 is linked to neoplasm.