In particular, cell shape changes in the SHF of mouse embryos lacking the 22q11.2 deletion syndrome candidate gene Tbx1 are associated with loss of basal filopodia and elevated aPKCz levels contributing to decreased proliferation and ectopic differentiation in the Tbx1−/− DPW12. The gene discussed is TBX1; the disease is 22q11.2 deletion syndrome.