SHH and central nervous system cancer: Similarly, we reported that Arl13b overexpression promotes SMO localization to GBM cilia in the absence of SHH, and that high levels of ARL13B and SMO expression in the tumors of glioma and gastric tumor patients was positively correlated with shortened post-diagnosis survival in these patients (Shao et al., 2017; Hoang-Minh et al., 2018).