EFNA2 and cancer: EphA7 is a particularly likely candidate for a pro-differentiation molecule because it has been characterized as a tumor suppressor in several cancers (Wang et al., 2005; Nakanishi et al., 2007; Oricchio et al., 2011) as well as a negative regulator of proliferation through reverse signaling with ephrin-A2 in the adult stem cell niches of the hippocampus (Holmberg et al., 2005) and hair follicle (Genander et al., 2010).