CDK4 and acute kidney injury: For example, Cdk4 and Cdk6 were members of Cluster 2, Pabla et al. found that G1/S-regulating cyclin dependent kinase 4/6 (CDK4/6) pathway is activated in nephrotoxic AKI (Pabla et al., 2015), and targeted inhibition of CDK4/6 pathway by small-molecule inhibitors resulted in inhibition of cell-cycle progression, amelioration of kidney injury, and improved overall survival.