The investigators will analyze the correlations between somatic mutations, specific clinical phenotypes (according to the WHO classification) and disease evolution. This will allow to: 1) identify new recurrent genetic mutations involved in the molecular pathogenesis of hematological malignancies; 2) define the role of mutated genes, distinguishing between genes which induce a clonal proliferation of hematopoietic stem cells, and genes which determine the clinical phenotype of the disease; 3) identify mutations which are responsible for disease evolution; 4) define the diagnostic/prognostic role of the identified mutations, and update the current disease classifications and prognostic scores by including molecular parameters.