p38 MAPK inhibitor IV is an ATP-competitive inhibitor of p38 MAP kinases with IC50 values of 0.13, 0.55, 5.47, and 8.63 μM for p38α, p38β, p38x, and p38δ, respectively, in vitro.[1] It also inhibits LPS-induced TNF-α and IL-1β cytokine production (IC50s = 22 and 44 nM, respectively) in human peripheral blood mononuclear cells.
Reference:
[1]. Liu, Y.C., Ko, C.C., Cheng, F.C., et al. Identification of a novel competitive inhibitor of p38α MAPK by a human PBMC screen. Biochim. Biophys. Res. Commun. 352(3), 656-661 (2007).