GDNF and neoplasm: These data have been confirmed by immunofluorescence analysis of BDNF and GDNF (Figure 4C–K, score Figure 4G, and Figure 4L, respectively) where control cells showed strong immunopositivity staining for both BDNF and GDNF (Figure 4C and Figure 4H, scores Figure 4G and Figure 4L, respectively); while the treatment with CX-4945 in a concentration-dependent manner significantly reduced the number of positive cells for both NFs (Figure 4D–F, score Figure 4G; Figure 4I–K, score Figure 4L), suggesting that reduction of BDNF and GDNF in U-87 cells slows down tumor progression.