IFNG and hemophagocytic syndrome: For patients with sHLH (40 EBV-HLH, 13 I-HLH, and 5 M-HLH totally in the LLQ and LUQ), patients in the LLQ presented a much higher 5-year OS than those in the LUQ (96.0 ± 3.9% vs. 64.1 ± 8.8%, p = 0.003), indicating high IL-10 to IFN-γ indicating a poor prognosis for patients with a low IFN-γ level.