IFNG and Hemophagocytosis: Most of our patients had cytopenia which presence can be explained by two factors, the first is hemopoiesis suppression by the highly elevated levels of inflammatory cytokines, such as IFN-γ released by activated T-cells, and the second is the phagocytosis of blood cells by overactivated macrophages [20] despite hemophagocytosis was present in bone marrow of eight of our studied patients (44.4%) which was similar to Cetica et al. [21] but differ from most of other studies which denoted that most of the patients had hemophagocytosis [11,15,22-24].