VEGFA and hepatocellular carcinoma: Specifically, T cells showed lower cytolytic activity in more heterogeneous tumors, and tumor-derived vascular endothelial growth factor (VEGF) drove microenvironmental reprogramming, suggesting a diverse ecosystem of HCC.32 A later study classified HCC into 2 clusters by differentially expressed genes (DEGs) in energy metabolism and showed that malignant cells of HCC had the highest overall metabolic activities.