GDNF and central nervous system cancer: The forest plot shows that EPB41L4A.AS1, GDNF.AS1, HAR1A, LINC00237, SLC25A21.AS1, SNA13.AS1, and WDFY3.AS2 are the protective factors with HR < 1, while LINC00092, LINC00265, LINC00339, LINC00665, PAXIP1.AS2, SNHG16, SNHG9 and SOCS2.AS1 are risk factors with HR>1 in glioma patients (Figure 3A).