Primary hemophagocytic phohistiocytosis (FHL) is a rare hereditary disease that causes immune dysfunction and has an incidence of 1.2/1,000,000.[1] It is induced by the mutations of various genes, including PRF1, UNC13D, and STX11 genes.[2] Such mutations could lead to the cellular toxicity induced by natural killer cells and granules of T cells, the uncontrolled activity of immune cells, over-release of inflammatory cytokines, and finally, immune-mediated multiple organ injuries,[3] among which injuries to the hematological system, liver, and spleen are the most prominent ones. This evidence concerns the gene PRF1 and hemophagocytic syndrome.