Interestingly, there were Wnt/β-catenin-related genes whose mRNA expression levels were noticeably increased in GBM compared with grade II and III glioma, and those genes were catenin beta 1 (CTNNB1), follistatin-like 1 (FSTL1), and casein kinase 1 alpha 1 (CSNK1A1) (Fig. 1B and C). Here, FSTL1 is linked to glioblastoma.