An active metabolite of dimethyl fumarate; an agonist of HCA2/GPR109A (EC50 = 9.4 µM); reduces neutrophil adhesion to endothelial cells stimulated with TNF, decreases CXCL2-directed neutrophil migration, and increases the expression of the Nrf2 target gene NQO1 in wild-type but not HCA2-/- macrophages; inhibits proliferation and induces differentiation in keratinocytes, as well as decreases TPA-induced levels of TNF-α in keratinocytes at 1 mM; reduces symptoms of EAE in mice at 1 mg/day