We have developed a prognostic assay on a custom gene expression array that detects EVI1 overexpression and low BAALC expression levels in individual AML patients as part of a multiplex genetic array that also detects AML with t(8;21), t(15;17), inv(16)/t(16;16), NPM1 mutations, and CEBPA double mutations with high accuracy (sensitivity and specificity > 95%). This evidence concerns the gene NPM1 and acute myeloid leukemia.