IRF6 and van der Woude syndrome: Although the study found no mutations in IRF6, the gene responsible for Van der Woude's syndrome, more recent research has shown that some genes responsible for syndromes involving cleft palate may also be candidate genes for non-syndromic cleft palate, with the most substantial evidence for the genes IRF6 and TBX22 (Marçano et al., 2004; Stanier and Moore, 2004; Zucchero et al., 2004; Nikopensius et al., 2010; Rahimov et al., 2012; Pegelow et al., 2014).