The diagnostic accuracy of uNGAL and TIMP-2*IGFBP7 in preterm infants who developed AKI during the first week of life was evaluate and the ROC curve of uNGAL1 as a predictor of AKI showed an area under the curve (AUC) of 0.92 (p = 0.024) with an optimal cut-off of 46.5 ng/ml (81%; 100%), while the ROC curve of TIMP-2*IGFBP7 1 showed an AUC of 0.59 (p = 0.330) with an optimal cut-off of 0.045 (ng/ml)2/1000 (38.1%; 100%). Here, TIMP2 is linked to acute kidney injury.