PDCD1LG2 and neoplasm: Finally, the observation that the off-rate of this molecule from PD-L1 and PD-L2 is longer than is expected from typical antibodies or fusion proteins, may partially explain the benefit conferred by PD1-Fc-OX40L in terms of tumor rejection, as compared to PD-1(L1) and OX40 agonist antibodies.