The PTPN11 gene encodes the phospho-tyrosyine phosphatase protein SHP-2. Constitutional mutations of this gene are involved in Noonan's syndrome, a developmental disorder in which children have a predisposition to develop a myeloid disorder called juvenile myelomonocytic leukemia. Recently, studies have shown that somatic mutations of PTPN11 can be found in children with myeloid malignancies. We evaluated the incidence of acquired mutation of PTPN11 in 76 adults with acute or chronic myeloid malignancies and summarized our results together with others published recently.