Fibroblast-derived HGF/SF has been shown to stimulate invasion and migration in a number of tumour types including squamous cell carcinoma (Matsumoto et al, 1994; Uchida et al, 2001), and we have demonstrated previously that exogenous HGF/SF induces expression of the type IV collagenases MMP-2 and -9 in squamous carcinoma cells (Bennett et al, 2000). This evidence concerns the gene HGF and squamous cell carcinoma.