- Cardiac morphogenetic defects and conduction abnormalities in mice homozygously deficient for connexin40 and heterozygously deficient for connexin45. Kr??ger, O., Maxeiner, S., Kim, J.S., van Rijen, H.V., de Bakker, J.M., Eckardt, D., Tiemann, K., Lewalter, T., Ghanem, A., L??deritz, B., Willecke, K. J. Mol. Cell. Cardiol. (2006)