CD274 and neoplasm: In the preliminary experiments, one anti-PD-L1 antibody improved cytotoxicity of B7-H3 CAR T cells at the high E:T ratio of 40:1 (Additional file 1: Fig. S14), suggesting anti-PD-L1 blockade should be able to prevent ﻿the immune-suppressive signaling of PD-L1 expressed by either tumor cells or T cells.