PDCD1LG2 and hepatocellular carcinoma: A distinct distribution of immune and stromal cell types was found between different HCC subtypes, in which tumors with higher PD-L1 or PD-L2 expression had more abundant infiltrating immune cells, including natural killer (NK)-cells, monocytes, B cells, different types of T cells, dendritic cells, and certain types of stromal cells (fibroblasts and endothelial cells) (Figure 7).