TNF and Splenomegaly: HPS is characterized by a high fever, pancytopenia, splenomegaly, liver dysfunction, coagulopathy, hyperferritinemia and hemophagocytosis in the bone marrow (BM) or other organs, which is caused by high levels of inflammatory cytokines, including interferon-γ, interleukin (IL)-12, IL-18 and tumor necrosis factor-α (TNF-α) (2).