CREB1 and pulmonary arterial hypertension: Taken together, these data indicate that ERK1/2 and CREB are potential players downstream of ADRA1A signaling in the hearts of PAH mice and that expression levels of Btg2, Egr1, Fos, and Atf3 are reduced via Ang II-mediated downregulation of Adra1a in PAH conditions.