TNF and Cryptococcal meningitis: JAK inhibitors exert immunosuppressive activities through the downregulation of several cytokines, such as interleukins, interferon-γ, and tumor necrosis factor-α,[3] and result in dysfunction of dendritic cells (DCs),[4] T-regulatory cells,[5] and natural killer (NK) cells.[6] Cryptococcal meningitis is known to occur particularly frequently in immunocompromised hosts.[7] However, there have been only 2 reports of cryptococcal meningitis in patients treated with JAK inhibitors.