The expression of Cx43 is down-regulated in experimental (Akar et al., 2004; Ai and Pogwizd, 2005) and clinical (Dupont et al., 2001; Kostin et al., 2004) studies of heart failure through recruitment of mitogen-activated protein kinase C-Jun NH2- terminal kinase (Petrich et al., 2002). This evidence concerns the gene GJA1 and heart failure.