PTPRH and gastric cancer: SAP-1 deficiency, however, severely reduced the number of large, but not small, adenomas in Apc haploinsufficient animals (Sadakata et al., 2009), in line with an earlier cell model study that pointed to an inhibitory role in stomach cancer cell growth and motility (Noguchi et al., 2001) but arguing against a role for Ptprh in the initial transformation of intestinal cells.