In the Sapphire study enrolling 744 critically ill medical and surgical subjects with a moderate–severe AKI occurring in 14 % of patients, the combination of TIMP-2 and IGFBP7 was significantly superior to all other existing markers of AKI with an AUC of 0.80 and also better than TIMP–2 (AUC 0.76) and IGFBP7 (AUC 0.79) alone [9]. Here, TIMP2 is linked to acute kidney injury.