CD274 and neoplasm: Given the maturation of small-interfering RNA (siRNA) techniques with nanotechnology, and because overexpression of human programmed death-ligand 1 (PD-L1) is crucial for T cell inactivation and immunosuppression of the tumor microenvironment, application of siRNA–PD-L1 has demonstrated positive progress in preclinical studies; however, the limited penetration of this compound into solid tumors remains a challenge.