CHEK1 and glioblastoma: In A712 GBM cells, 100 μM P4 reduced levels of 1433Z/YWHAZ (14‐3‐3 Protein Zeta), which involves in regulation of apoptosis; Chk1/Chk2(Cds1) mediated inactivation of Cyclin B:Cdk1 complex; and TP53 regulation of metabolic genes.