5Z-7-Oxozeaenol is a potent irreversible and selective inhibitor of transforming growth factor (TGF)-β-activated kinase 1 (TAK1, IC50, 8.1 nM), less active on MEK1 (IC50, 411 nM). 5Z-7-Oxozeaenol prevents inflammation by inhibiting the catalytic activity of TAK1 MAPK kinase kinase. 5Z-7-Oxozeaenol is also an inhibitor of VEGF-R2, with an IC50 of 52 nM. 5Z-7-Oxozeaenol has inhibitory activity against VEGF-R3, FLT3, PDGFR-β, B-RAF VE and SRC, with IC50s of 110, 170, 340, 6300 and 6600 nM, respectively. 5Z-7-Oxozeaenol inhibits JNK/p38 paythway, but it is not a direct inhibitor and is signal specific. 5Z-7-Oxozeaenol suppresses the PMA-induced AP-1 activity almost to the basal level in the KT cells, but has no effects on IL-1-induced NF-kB activity in the KK cells.