CD47 and cancer: Similarly, as CD47 and PD-L1 are critical innate and adaptive checkpoints, Lian et al. [94] designed high-epithelial cell adhesion molecule cancer cells targeting cationic liposome (LPP-P4-Ep) that contains si-CD47 and si-PD-L1, which could knockdown both CD47 and PD-L1 proteins.