PDCD1LG2 and malignant pleural mesothelioma: Nivolumab, a human monoclonal antibody that inhibits interactions between the programmed cell death protein-1 receptor and its ligands (programmed death-ligand 1 [PD-L1] and PD-L2), was approved in Japan (August 2018) for patients with pemetrexed–platinum doublet-treated MPM on the basis of the results of the Multicenter, Open-label, Single-arm, Japanese Phase II study in Malignant Pleural Mesothelioma (MERIT) study,5 which enrolled 34 Japanese patients.