In glioblastoma cells, high PTK2 expression can increase the expression of CCND1 and CCNE, reduce the expression of CDKN1B (p27Kip1) and p21Waf1, and enhance the activity of CDK4, thereby promoting the G1/S phase transformation of glioblastoma cells [84]. This evidence concerns the gene CDKN1B and glioblastoma.