Ensuing screening of the Twist1+/−:Axin2lacZ/+ double transgenic COR sutures for complete unilateral or bilateral craniosynostosis revealed a frequency of 0% in wild-type mice, as expected; 83% in Twist1+/− mice; and 0% in Twist1+/−:Axin2lacZ/+ double transgenic mice. This evidence concerns the gene TWIST1 and craniosynostosis.