DKK1 and neurodegenerative disease: Further, in vivo studies in rat and mouse and in vitro on neuronal cultures indicated that increased Dkk1 protein expression may contribute to cell death in cerebral ischemia, epilepsy, and neurodegenerative diseases (Cappuccio et al., 2005; Busceti et al., 2007; Mastroiacovo et al., 2009; Rosi et al., 2010).