PDCD1 and hereditary clear cell renal cell carcinoma: Accumulating data have suggested that intra-tumoural expression of PD-L1 could be a potential biomarker to predict the clinical response to anti-PD-1/PD-L1 therapies in patients with melanoma, non-small-cell lung carcinoma, and renal cell carcinoma.12,14,21,38,39 To characterise and investigate PD-L1 expression in HCC in detail, we performed double staining using TSA-IHC in 453 patients with HCC.