IFNG and X-linked lymphoproliferative disease: As shown in Figure 1B, the pattern of EBV-HLH was significantly elevated IL-10 and IFN-γ with slightly elevated IL-6, and IFN-γ usually higher than IL-10; the pattern of I-HLH was moderately elevated IL-6, IL-10, and IFN-γ; the patterns of M-HLH and FHL were similar, presenting markedly elevated IL-10 and IFN-γ with slightly elevated IL-6, and IFN-γ usually lower than IL-10; the pattern of XLP was moderately elevated IL-6 and IL-10, while IFN-γ was normal or slightly increased.