PDCD1 and hepatocellular carcinoma: Similarly, PD-L1 expression in HCC has been reported as a predictive biomarker for poor prognosis and can also utilised as an important tool to predict the response to anti-PD-1 antibodies; however, identifying other immune biomarkers could play an important role to further improve patient outcome as PD-L1 levels fluctuate along the course of the disease and only expressed in 30% of HCC tumours [89].