Over 50% of patients with Noonan syndrome and 85–90% with Noonan syndrome with multiple lentigines, respectively, carry activating or inactivating germline mutations in PTPN11 (protein tyrosine phosphatase non-receptor 11), the gene encoding cytoplasmic Src homology-2 protein tyrosine phosphatase (SHP-2) [1]. The gene discussed is PTPN11; the disease is Noonan syndrome.