TGFB1 and neoplasm: Complementary, other immune factors may also be involved in MPM progression are enriched infiltration of M2 macrophages, along with impaired T CD8+ CD163+ cell functionality, caused by macrophage-released arginase, IL-10, and TGF-β, and tumor-associated fibroblasts (10), which are known to create an immunosuppressive microenvironment (19).