Various growth factors and their receptors, including hepatocyte growth factor (HGF)/c-Met, epithelial growth factor (EGF)/EGF-R, and the vascular endothelial growth factor (VEGF) family/VEGF-Rs, are reported to be involved in tumour–stromal interactions (Nakamura et al, 1997; Turkeri et al, 1998; Kajita et al, 2001). This evidence concerns the gene HGF and neoplasm.