(S)-p38MAPK inhibitor III is a methylsulfanylimidazole that inhibits p38MAPkinase (IC50 = 0.90 μM in vitro). It is cell-permeable, potently blocking the release of TNF-α and IL-1β from human peripheral blood mononuclear cells (IC50s = 0.37 and 0.044 μM, respectively).