FR 180204 is a novel and selective inhibitor of extracellular signal-regulated kinase (ERK), which may be a potential new therapy for rheumatoid arthritis. FR 180204 inhibited ERK1 and ERK2 with an IC50 value of 0.51 uM (Ki = 0.31 uM) and 0.33 uM (Ki = 0.14 uM), respectively. FR 180204 may be useful as a therapeutic agent for the treatment of cancer, immune diseases, ischemic brain injury, and obesity. In a mouse model of dengue virus (DENV) infection, FR 180204 limits hepatocyte apoptosis, reduces DENV-induced liver injury, and improves Clinical parameters.