However, the finding that gain of function N-ethyl-N-nitrosourea-induced mutation in mouse results in a highly similar ocular phenotype to that observed in the Tfap2a knockout mouse leaves open the possibility that some missense mutations may in fact mediate their effect in human BOFS patients by increasing TFAP2A transcriptional activity [26]. Here, TFAP2A is linked to Branchio-oculo-facial syndrome.