AQP2 and acute kidney injury: As shown in Figure 4B, AQP2 abundance using specific AQP2 antibody 19-64-17 was significantly higher in kidney transplant recipients with acute kidney injury (median 0.20; IQR 0.09 to 0.28) compared to immediate allograft function (median 0.08; IQR 0.04 to 0.18; p < 0.01 by Mann–Whitney test).