TWIST1 and cleidocranial dysplasia 1: In fact, altered FGFRs and Twist activity largely associate with downstream modulation of Runx2 expression and/or activity—making Runx2 a potentially key molecule of mechanistic convergence for CS.(38,39) Overall, Runx2's activities are etiopathologically involved in many congenital craniofacial anomalies, including CCD, in humans caused by Runx2 mutations.(4,5)