NPM1 gene mutations appear to occur more frequently in adult female AML patients [14-16] and also tend to be associated with: a) higher white blood cell count, b) monocytic differentiation (in particular FAB M5b AML subtype) [17], c) wide morphologic spectrum, d) multilineage involvement [9], e) lack of CD34/CD34-negativity [7,9,11], f) normal cytogenetics [18], g) a decreased prevalence of CEBPα mutations [17], h) high frequency of FLT3-ITD gene mutation [18] and i) a trend toward favorable clinical outcome, especially in patients without a FLT3 gene mutation [7,15]. The gene discussed is NPM1; the disease is acute myeloid leukemia.