CDK4 and glioblastoma: The exogenous expression of CDK4 mutants negates the inhibitory effect of RSV and RO4929097 on the motility/invasion of glioblastoma cells and enhances the expression of stemness-specific markers GFAP, CD13.3, and SOX2, and the EMT markers TWIST and SNAIL, as well as the size/formation capability of the neurosphere [83].