CDK1 and meningioma: Gogineni et al.231 found that when meningioma cells were subjected to IR, G2/M arrest could be triggered quickly, and the key event in the underlying mechanism was the phosphorylation of CHK2, CDC25C, and CDC2; this phosphorylation interferes with CHK2 activation and the cyclin B1/CDC2 interaction, resulting in permanent arrest followed by apoptosis.