PTPN11 and Noonan syndrome: With the interactive sequence viewer on the Search page, we can quickly observe that there is a PDB structure (4H1O) available for the SHP2 mutant D61G (https://www.rcsb.org/structure/4H1O), where the aspartate residue of the blocking loop is replaced by a glycine (Figure 5A): this is an oncogenic mutation that was identified in multiple disease conditions, including Noonan syndrome and leukemia (58,59).