PDCD1 and neoplasm: In the mouse MC38 colorectal cancer model and A375 melanoma model with PD-L1 knock in, the use of IBI323 (mAb double blocking PD-L1 and LAG3) showed a superior anti-tumor effect by inhibiting the interaction between PD-1/PD-L1 and LAG3/MHC-II, and enhanced the activity of immune stimulation, increasing the amount of CD4+ and CD8+ T cells (71).