CD19 and neoplasm: Up-regulation of checkpoints including programed death ligand-1 (PD-L1) within the tumor microenvironment of Non-Hodgkin lymphoma (NHL) patients after axicabtagene ciloleucel treatment has provided the rationale for initiating a clinical trial investigating the efficacy of CD19 CAR T-cells in combination with the anti-PD-L1 antibody Atezolizymab (Zuma-6, NCT02926833) [63].