XPO1 and Apert syndrome: We thus tested U0126, a specific MEK1/2 inhibitor that was also previously reported in the treatment of craniosynostosis in an Apert syndrome mouse model [7] and KPT-330, a nonreversible selective inhibitor of the nuclear exportin XPO1/CRM1 that is being tested as a potential antitumor drug [28,29,30].