Silibinin (0–200 μM) remarkably downregulated programmed death-ligand 1 (PD-L1) expression by inhibiting hypoxia-inducible factor-1α/lactate dehydrogenase-A (HIF-1α/LDH-A) mediated cell metabolism in EBV-positive NPC [103]. Here, LDHA is linked to nasopharyngeal carcinoma.