NPM1 and acute myeloid leukemia: To evaluate whether PRL-3 is an independent prognostic marker for survival in AML patients, multivariable Cox-regression was performed in Cohort 1 (n = 221) with parameters including sex, age, cytogenetic risk group, karyotype, FAB group, FLT3 mutation status, NPM mutation status and PRL-3 mRNA expression (Table 1).