CDK6 and cancer: Furthermore, some cancer-related factors were detected by the western blot assay, accompanied by the down-regulation of Akt (protein kinase B, PKB), P-Akt (phosphorylated AKT), CCND1 (cyclin D1) and CDK6 (cyclin-dependent kinase 6) levels, as well as the up-regulation of MAPK9 (mitogen-activated protein kinase 9) in shMCM8 group (Fig. 3F).