SMAD4 and digestive system cancer: Reassuringly, the resulting list includes several known colon tumor suppressors such as APC (Fearnhead et al, 2001; Aoki & Taketo, 2007), TCF7L2 (Hazra et al, 2008; Slattery et al, 2008), MCC (Kinzler et al, 1991), PTEN (Nassif et al, 2004; Song et al, 2012), and SMAD4 (Miyaki et al, 1999; Alazzouzi et al, 2005).