NPC1 and injury: For example, brain injury activates endogenous NPCs, leading to an expansion of the size of the NPC pool, migration, and neurogenesis (Parent et al., 2002; Jin et al., 2003; Ahmed et al., 2014) Administration of growth factors and small molecules can similarly promote NPC expansion, migration and differentiation (Kolb et al., 2007; Hunt et al., 2010; Dadwal et al., 2015).