MFN2 and hydrops fetalis: However, the expression level of mitofusin 2 (MFN2), which creates a hub for autophagosome formation, was significantly decreased in HF myocytes (56.73 ± 14%, N = 5 hearts, p < 0.01) compared to nonfailing age-matched myocytes (99.9 ± 15%, N = 3) and myocytes from the young hearts (taken as 100%, N = 5) (Figures 3A,D).