STAT1 and hepatocellular carcinoma: Western blot analysis indicated that re-expression of STAT1WT, but not STAT1Y701A, could restore the STAT1 KD-induced decrease in PD-L1 protein levels in HCC cells, while concurrent overexpression of HKDC1 could further increase PD-L1 accumulation in cells overexpressing STAT1WT, but not STAT1Y701A (Fig. 3i and Supplementary Fig. 4i).