2009). Consequently, Cx40 knockout (Cx40KO) mice have a defective TGF mechanism, corresponding functionally to papillectomy (Sorensen et al. 2012). Preglomerular arterioles isolated from Cx40KO mice are unable to conduct a Ca2+ signal elicited by electrical stimulation (Sorensen et al. 2012). The lack of Cx40 also results in increased renin release and hypertension in these mice (Wagner et al. 2007). This evidence concerns the gene GJA5 and Hypertension.