CD8A and neoplasm: The tumor microenvironment (TME) in hepato-pancreatico-biliary (HPB) cancers is a disordered inflammatory state characterized by infiltration of immune cells with paradoxically immunosuppressive phenotypes, such as regulatory T cells, exhausted CD4+ and CD8+ T cells, M2 macrophages, myeloid-derived suppressor cells (MDSC), and cancer-associated fibroblasts (CAF) (9).