In order to gain insight into the molecular mechanisms contributing to the frequent co-occurrence of syndromic or non-syndromic tooth agenesis and OFCs, a systematic review revealed 84 articles including phenotype and genotype description of 9 genomic loci and 26 gene candidates underlying the co-occurrence of the combined congenital defects, one of them being IRF6 (Phan et al., 2016). Here, IRF6 is linked to tooth agenesis.