Homo sapiens
Protocols: All patients were enrolled at Icahn School of Medicine at Mount Sinai (ISMMS) and provided informed consent for tissue biobanking. Samples were provided by the ISMMS Biorepository. All patients were diagnosed with hepatocellular carcinoma based on the EASL guidelines, and were treatment-naïve prior to surgical resection. The different regions were sampled allowing for at least 1 cm of distance between each other. The final number of regions per tumor varied according to tissue availability and presence of tumor necrosis. Each tumor and adjacent tissue sample was split in half to allow for mirrored histological and molecular analysis. Half of the sample was immediately stored in RNA-later (Qiagen) for 24 hours at 4°C, and subsequently at -80°C, and the other half was embedded in OCT and stored at -80°C. DNA was extracted from samples using the DNeasy blood and tissue kit (Qiagen) following manufacturer's instructions. Target enrichment was performed using Agilent SureSelect Custom Capture for a panel of 58 genes that are known drivers of hepatocellular carcinoma. Libraries were prepared using the TruSeq DNA Library Prep Kit HT following manufacturer's protocol.