CXCR4 and glioblastoma: Other factors such as M2 receptors, CXCR4, POL5551, LonP1, CT-L, PPARα, and SUMO are involved in regulating various aspects of glioblastoma progression and response to therapy, as noted by Cristofaro et al. [69], Gagner et al. [89], Douglas et al. [72], Hofstetter et al. [76], and Bernstock et al. [83].