Given the clinical symptoms of patients from which the missense mutations studied here were identified (as shown in Figure 5E, all the H-Ras mutations are associated with Costello syndrome (CS); most of the Raf-1 mutations are associated with Noonan syndrome (NS); most of the B-Raf and all of the Mek mutations are associated with cardio-facio-cutaneous syndrome (CFCS)), the result in Figure 5A–5D suggests that NS and CFCS may share some degree of similarity in terms of disease development. Here, HRAS is linked to Costello syndrome.