PDCD1 and neoplasm: In C57BL/6-hPD-1/hCD137 mice bearing another colorectal tumour cell line (MC38), compared to hIgG, IBI319 showed clear dose-dependent antitumour efficacy at 0.3, 1, 3, and 10 mg/kg with tumour growth inhibition (TGI) rates of 3, 42, 33 and 91%, respectively (Fig. 3b-left).