WNT1 and cleft palate: Indeed, the previously described conditional ablation of Tgfbr2 in the neural crest cell lineage (Wnt1-Cre; Tgfbr2floxl/flox) was also in the C57BL/6J background [18], further reiterating that the background may not be the attributing factor for the lack of cleft palate phenotype in our analysis.