Fig. 2. Signaling pathways for cell migration mediated by p38. Chemotactic factors and growth factors, such as fMLP, VEGF and FGF, activate MKK3/6 via their upstream MAPKKKs, such as MLK3. Activated MKK3/6 phosphorylate and activate p38, which in turn activates MAPKAPK2/3. The active MAPKAPK2/3 then phosphorylate HSP-27, resulting actin reorganization and cell migration. MAPKAPK2/3 also phosphorylates the p16-Arc of the Arp2/3 complex and 5-lipoxygenase, whereas p38 phosphorylates paxillin and caldesmon. These might play roles in cell migration. Orange lines represent speculative pathways.