SERPINE1 and acute kidney injury: Aged WT mice showed histological evidence of AKI only at 48 h (92% increase from control) which did not reach significance (p = 0.068), while aged PAI-1 KO mice showed earlier and significant evidence of AKI at 24 h (144% increase, p = 0.013), which was sustained through 48 h (201% increase, p = 0.0005).