HGF and neoplasm: As mentioned above, serum HGF is elevated in individuals with cancer.7–11 HGF is released from cancer cells11,12 and stimulates not only tumor cell invasion but also neovascularization as a potent endothelial growth factor.13,20–23 If participants who died within 5 years had subclinical cancer at baseline, they might have had higher baseline HGF levels.