Previous clinical studies have reported that overexpression of HGF and/or c-Met is associated with the survival rate of patients with malignant tumours, including NSCLCs (Ichimura et al, 1996; Takanami et al, 1996; Siegfried et al, 1997), breast cancers (Edakuni et al, 2001), and thyroid cancers (Ramirez et al, 2000). This evidence concerns the gene HGF and thyroid cancer.