The higher serum osmolality in AQP1-KO mice during endotoxemia in the absence of water repletion was associated with higher AQP2, AQP3, and Na+-K+-2Cl− cotransporter type 2 expression and a lower Na+/H+ exchanger type 3 protein expression than that in WT mice during endotoxemia [16] [Table 1]. Here, AQP2 is linked to serum lipopolysaccharide activity.