RAC1 and cancer: We next explored whether SF3B1 pharmacological blockade, using pladienolide B altered the splicing process of some critical genes implicated in GBM progression which have been previously reported to be associated with cancer-related signaling -pathways (i.e., KLF6/CRK/MST1R/CASP2/RAC1/MCL1/BIRC5/SPP1/BCL2L1).