Given that PE migration to the heart and epicardial formation were not affected, the authors concluded that b-catenin has a specific role in induction of the coronary vascular smooth muscle lineage.
Retinoic acid and adenoviral overexpression of Raldh2 in quail PE explants decreases alpha-SMA expression, while inhibition of retinoic acid signaling in vivo leads to increase expression of alpha-SMA.