To extend the finding of Siah2 expression in a defined genetic context in which Shh signaling is genetically activated in GNPs, we performed  immunofluorescent staining for Siah2 on samples of Shh-driven MBs obtained from the Ptc+/− P18KO MB mouse model34 (Fig. 2b). The gene discussed is SIAH2; the disease is Mobius syndrome.