Although JAK2 mutant tumor cells can produce interferon (IFN)-γ, the JAK2–signal transducer and activator of transcription _(STAT) signal pathway cannot be activated by IFN-γ and cannot upregulate the expression of PD-L1, which leads to the weak killing effect of IFN on JAK2 mutant tumor cells. This evidence concerns the gene IFNG and neoplasm.