The study of HGS and HGS/C overexpression in cancer cells demonstrated that HGS promoted tumorigenicity in B16 cells and COLO205 cells, whereas HGS/C suppressed it: (1) HGS promoted the TGF-β-SMAD and Wnt-β-catenin signal transduction, whereas HGS/C suppressed them; (2) HGS promoted the colony-formation ability in soft agar medium and promoted their tumor-growth ability in mice, whereas HGS/C suppressed them. The gene discussed is TGFB1; the disease is cancer.