KCNJ8 and Cowden syndrome 1: The present study demonstrates that, when introduced into the mouse genome, the most common CS-associated ABCC9 mutation (encoding human SUR2[R1154Q]) resulted in qualitatively the same cardiovascular features as the SUR2[A478V] and Kir6.1[V65M] mutations (26), providing further confirmation of the common cardiovascular outcome of vascular dilation and cardiac enlargement resulting from SUR2- or Kir6.1-dependent KATP GOF in CS.