After mitogenic stimuli of cells in G1, cyclin D bind to cyclin-dependent kinases (CKD) and activate a downstream process that led to the S phase, which is regulated by the cyclin E-CDK2 complex, while the G2/M transition is under control of cyclin B-CDK1 complex (Mens and Ghanbari, 2018). Here, CDK2 is linked to chronic kidney disease.