AQP7 and obesity due to melanocortin 4 receptor deficiency: The site of AQP7 expression, exclusively in endothelial cells (Skowronski et al., 2007; Lebeck et al., 2012b) or in endothelial cells and adipocytes (Laforenza et al., 2013; Miyauchi et al., 2015), could account for the susceptibility of mice to develop obesity (Skowronski et al., 2016).