INCB018424 is an inhibitor of JAK1/2 that is clinically used to treat rheumatoid arthritis and myelofibrosis. INCB018424 exhibits anticancer, anti-inflammatory, and antiviral activities. In myeloma cells, INCB018424 inhibits cell growth. INCB018424 also inhibits in vitro infection by HIV-1, HIV-2, and SHIV by preventing viral replication in lymphocytes. In animal models of CCL4-induced hepatic injury, INCB018424 prevents inflammation by decreasing neutrophil and macrophage infiltration, suppressing activation of NF-κB, and limiting release of TNF-α, IL-10, and IL-1β.