Numerous studies have shown the involvement of TGF-β1 in different types of cancer, including gastric, colorectal and breast cancer (Naef et al, 1997; Nakamura et al, 1998; Maehara et al, 1999; Saito et al, 1999; Desruisseau et al, 2006). The gene discussed is TGFB1; the disease is cancer.