PAX7 and scoliosis: Thus, our results indicate that most defects seen in Myh3Δ/Δ mice such as reduced grip strength and fiber size, elevated muscle fibrosis, altered levels of MyHC‐IIa and ‐slow, changed Pax7 levels and scoliosis are mediated by increased YAP pathway activation, which are rescued by treatment with the YAP inhibitor CA3 during early postnatal stages.