HGF and neoplasm: In mice harboring intracranial xenografts of HK296 cells stably overexpressing circ-HGF RNA or the C-HGF ORF, these xenografts displayed increased tumor growth and shortened the time of tumor onset (empty vector & pLKO.1, tumor onset = 21 days; circ-HGF, tumor onset = day 8; pLKO.1-C-HGF, tumor onset = day 10) relative to controls (Fig. 5E).