TLR4 and cancer: Since cancer cell membrane-expressed PD-L1, not PD-L1 in cytoplasm, has biological significance [24], and is related to PD-L1 inhibitor treatment outcomes [25], our study shows that PAUF is unlikely to impact the PD-1 and PD-L1 treatment outcomes, even if it can change PD-L1 level in cytoplasm via TLR4.