MYF6 and hydrops fetalis: Furthermore, the expression levels of both developmental myosins, embryonic (MYH3) and neonatal (MYH8), were substantially upregulated in HF-derived skeletal muscle biopsies, which along with the upregulation of myogenic regulatory factor Myf6 detected in HF-derived samples (Figures 1(d)–1(f)) may indicate the chronic shift to developmental program and pathological stimulation of muscle regeneration in HF [24, 25].