In a mouse model of limb ischemia, bFGF was found to directly stimulate the expression of HGF mRNA through the p42/44 MAPK pathway in the early stage, and to indirectly induce HGF expression by stimulating the secretion of endogenous PDGF-AA in the later stage (Onimaru et al., 2002). This evidence concerns the gene HGF and limb ischemia.