AQP9 expression in 80 cases of leukemia. (A) AML M3 (APL) expressed significantly higher AQP9 levels (P = .027) than all the other subtypes of acute myeloid leukemia (M0, minimally differentiated; M1, without maturation; M2, with maturation; M4, myelomonocytic; M5, monoblastic; M6, erythroid; M7, megakaryoblastic; MDS→AML, acute myeloid leukemia evolving from an antecedent myelodysplastic syndrome). The solid line indicates mean; dotted line, standard error of the mean. (B) AQP9 expression was comparable in AML M2 and APL (P = .75) but was significantly different in APL and other subtypes of AML (P = .009). (C) ALL expressed comparable AQP9 levels compared with AML.