ASCL1 and central nervous system cancer: However, ASCL1 is also expressed in transit amplifying cells derived from adult subventricular neural stem cells, proliferative OPCs, dividing glioma cells and even neuroendocrine cells of endodermal tissues such as the lung, and is crucially involved in small lung cancer formation (Paliouras et al., 2012; Battiste et al., 2007; Park et al., 2017; Altree-Tacha et al., 2017).