IFNG and plexiform neurofibroma: Schwannomas and neurofibromas, which have an inflammatory immune microenvironment of T and B lymphocytes and tumor-associated macrophages (TAMs), are driven by upregulation of cytokines such as interferon γ (IFNγ), interleukin-1 (IL-1), IL-6, and tumor necrosis factor α (TNF-α).57