HLH is characterized by severe symptoms and a high mortality rate.[1, 2, 3] Activated macrophages play a crucial role in HLH by engulfing many blood cells.[4, 5, 6, 7, 8, 9] During the pathogenic process, macrophages also release high levels of cytokines such as IFN‐γ, TNF‐α, and IL‐6, leading to a cytokine storm.[10, 11, 12] In addition, aberrant macrophages can promote the activation of cytotoxic T cells and natural killer (NK) cells, further exacerbating cytokine release. The gene discussed is IFNG; the disease is hemophagocytic syndrome.