In this study, we show that although RAPA alone does not mediate any significant change in PD-L1 expression, the combination of RAPA + Honokiol markedly down-regulates the basal PD-L1 on renal cancer cells; and importantly, this combination treatment completely blocks c-Met-induced PD-L1 over-expression. This evidence concerns the gene TRERF1 and renal carcinoma.