Identification of such key genes downstream of gata4 and of other cardiogenic gata genes promises to provide a better understanding of human cardiomyopathies resulting from GATA4 mutations (Garg et al., 2003, Rajagopal et al., 2007) and mouse phenotypes such as acardia in Gata4 and Gata6 double mutant embryos (Zhao et al., 2008). This evidence concerns the gene GATA6 and cardiomyopathy.