The purpose of this study is to compare the efficacy of the available second-line therapies—specifically immune checkpoint inhibitors (IO), defined as the use of any programmed cell death protein 1 (PD-1) inhibitors nivolumab or pembrolizumab—compared to vascular endothelial growth factor receptor (VEGFR2) multi-tyrosine kinase inhibitors (mTKIs) or monoclonal antibodies (non-IO), namely sorafenib, regorafenib, cabozantinib, and ramucirumab, for the treatment of advanced HCC and to investigate for potential patient subgroup variables that influence efficacy. The gene discussed is PDCD1; the disease is hepatocellular carcinoma.