Apilimod is a small molecule that inhibits IL-12 and IL-23 production - cytokines that are involved in autoimmune diseases through the prevention of nuclear translocation of c-Rel. It suppresses the Th1, but not the Th2, response, resulting in reduced inflammation in a mouse model of inflammatory bowel disease. Apilimod inhibits the production of IL-23p19 and IL-12/IL-23p40 subunits while decreasing skin inflammation in a clinical study of patients with psoriasis. Apilimod inhibits phosphatidylinositol-3-phosphate 5-kinase (PIKfyve; IC50 = 14 nM), which is necessary and sufficient for suppression of IL-12/IL-23p40 expression. MW: 610.7. Purity ≥98% by HPLC