CXCL5 and cancer: Despite previous reports that the ERK signaling pathway is involved in the activation of MMP2 in cancer cells [44] and that MMP2 secretion from human ciliary muscle cells is a PKC- and ERK1/2-dependent process [45], we conclude that CXCL5 promotes the migration of VSMCs in an ERK1/2-independent pathway and that the Akt/p38 signaling pathway governs the migration of VSMCs induced by CXCL5.