P21, as a cyclin-dependent kinase inhibitor encoded by the CDKN1A gene, inhibits the formation of the CDK2-CDK1 complex and mediates the G1 phase arrest of p53- dependent cell cycle. Numerous studies have shown that lncRNAs regulated the cell cycle by affecting the expression of p21 protein, leading to the proliferation of glioma cells. This evidence concerns the gene CDKN1A and central nervous system cancer.