Programmed death-ligand 1 (PD-L1) and programmed death-ligand 2 (PD-L2) genes expression, due to the inhibition of CAR T-cell antitumor activity (T cell exhaustion), is one of the most critical challenges for effective use of CAR T-cell in solid tumors and hematological malignancies [155, 156]. This evidence concerns the gene PDCD1LG2 and hematologic disorder.