By contrast, FRG1 is an important for normal development of the vertebrate and invertebrate musculature and vasculature [36–39]; overexpression of FRG1 leads to a severe myopathy in mice, adversely affects muscle development and angiogenesis in Xenopus, disrupts muscle structure and organization in C. elegans, and causes primary defects in myogenic stem cells [27, 36–40]. Here, FRG1 is linked to myopathy.