“…Several studies also implicate RA-RARα signaling in the regulation of the expression of apelin and apelin receptor (APJ) expression in human and rat endothelial cells and in vivo in hypertensive rats (Shi, Yuan, et al, 2017;Zhong et al, 2005). APJ is specifically expressed in sinus venosus-derived coronary vessels, and APJ signalling via its alternate ligand, elabela, was required for their angiogenic sprouting (Chen et al, 2014;Sharma, Ho, et al, 2017). Therefore, the effect of altered RA-signaling on coronary development in vivo is likely to reflect the aggregated impact of altered RA on myocardial expansion, vascular development and fetal erythropoiesis (Bohnsack, Lai, Dolle, & Hirschi, 2004;Brade et al, 2011;Canete, Cano, Munoz-Chapuli, & Carmona, 2017;Chanda, Ditadi, Iscove, & Keller, 2013;Pawlikowski, Wragge, & Siegenthaler, 2019).…”