IL17A and stroke disorder: While some studies have reported that IL-17a negatively regulates the proliferation of mouse NPCs in vitro (Li et al., 2013; Tfilin and Turgeman, 2019) as well as of both adult-born neuroblasts and mature neurons in the hippocampus in vivo under physiological conditions (Liu et al., 2014), another study has suggested that this cytokine does not alter the proliferation of subventricular zone NPCs during stroke recovery, but instead increases their survival in vivo (Lin et al., 2016).