Moreover, although microglial activation has been reported in methotrexate‐necrotizing leukoencephalopathy, JBE, and CJD,18, 19, 20 the inhibition of IL‐1 was ineffective in our patients, and dysregulated innate immunity may not be the main force driving pathogenesis. The gene discussed is IL1B; the disease is Creutzfeldt Jacob disease.