ACTA1 and acute kidney tubular necrosis: We found in previous studies that there was a large increase in α-smooth muscle-actin (α-SMA), fibronectin, and endothelin expression in the tubulointerstitial compartment of kidneys from patients with acute tubular necrosis after renal transplantation, which was associated with increased urinary levels of transforming growth factor β (TGF-β).