KLK1 and acute kidney injury: Although previous reports of KLK1 excretion in AKI indicated diminished excretion in both rodent models [6,21,22] and AKI/ATN in the setting of human renal transplantation [9], we noted a ~11-fold elevation of KLK1 excretion in our established AKI subjects (Tables 1-3; Figure 2).