IGFBP7 and acute kidney injury: With regard to our secondary end points, we also found that for certain functional stages (no AKI and stage 2), a [TIMP-2] × [IGFBP7] level greater than 2.0 (ng/mL)2/1000 was associated with a longer hospital LOS and, only for patients with stage 2, a lower rate of full recovery from AKI.