In order to investigate whether the induction of cell cycle arrest before renal IRI also has a renoprotective effect in vivo, we injected a potent CDK4/6 inhibitor (PD 0332991, 100 mg/kg) to interrupt the cyclin kinase–dependent cell cycle regulation and induction of G1 cell cycle arrest in WT mice before inducing renal IRI (36), which attenuated AKI severity, as shown by a reduction in renal neutrophil recruitment and by serum creatinine levels in the plasma (Figure 5, A and B). Here, CDK4 is linked to acute kidney injury.