Fever, hepatosplenomegaly, hyperferritinemia, and pancytopenia are common clinical manifestations of HLH, which are accompanied by increased levels of cytokines, such as interferons (IFNs), interleukin-1β (IL-1β), IL-18, IL-6, and tumor necrosis factor (TNF) (10–13). Here, TNF is linked to isolated hyperferritinemia.