Consistent with our findings here in the Hoxa2−/− mice, Osr2−/− exhibit increased osteogenic centers of the palatal process of the palatine bone prior to the elevation of the palatal shelves at E13.5 and in addition to defective cell proliferation, enhanced osteogenesis could contribute to cleft palate phenotype in Osr2−/− mice (Fu et al., 2017). Here, OSR2 is linked to cleft palate.