TBX1 and cleft palate: In the present study, functional explant assays and microarray analysis of gene expression was carried out in the palatal shelves of E13.5 mouse embryos WT, heterozygous or mutant for Tbx1. This was prompted by the knowledge that Tbx1 is strongly expressed in epithelium of the palatal shelves throughout palatogenesis, mutant embryos demonstrate cleft palate with complete penetrance [23, 24, 47, 48] and the findings that Tbx1 has multiple potential roles during normal palatal shelf elevation, elongation and adhesion [47, 48].