Recent evidence shows that the differentially expressed in normal and neoplasia (DENN) domain proteins form a large family of Rab GEFs (Allaire et al., 2010; Levivier et al., 2001; Sato et al., 2008; Yoshimura et al., 2010); however, none have been reported to act on Rab11-related GTPases. The gene discussed is RAB11A; the disease is neoplasm.