Stress in isolation may be benign, but when it coexists with dysfunction, it may signal actual damage.17 However, this interpretation is challenged by the work of Husain-Syed and colleagues,18 who demonstrated that an increased urinary [TIMP-2] × [IGFBP7] level after cardiac surgery was associated with loss of kidney functional reserve at 3 months even in the absence of AKI. This evidence concerns the gene TIMP2 and acute kidney injury.