GDNF and central nervous system cancer: Compared with non-tumor brain tissues, the expression levels of SNAI3-AS1, GDNF-AS1, WDFY3-AS2, and CPB2-AS1 showed an overall downward trend (Figure 8A), and the expression level of SBF2-AS1, PAXIP1-AS2, SNHG18, and PVT1 showed an overall upward trend in glioma tissues (Figure 8B).