GJA4 and Chylothorax: Cx47 loss-of-function mutations could directly affect LV function, but Cx47−/− mice do not develop the severe chylothorax observed in Cx37−/−; Cx43+/− mice or in mice with LEC-specific knockout of Cx43.21 The data in Figures 2 and 4 suggest that complete loss of Cx47 results in only relatively mild LV back leak with little change in the ability to close.