GSK3B and Alzheimer disease: Of note, CRMP-2 has a role in Numb-mediated endocytosis (Nishimura et al., 2003), is phosphorylated early in AD (Cole et al., 2007) and is a substrate for glycogen synthase kinase 3 (Gsk3β; Cole et al., 2004), a known molecular player in AD (Kremer et al., 2011).