This was tested by inhibiting YAP signaling by treatment with the small molecule CA3, which led to increase in muscle fiber size, decrease in MyHC‐IIa fibers, increase in MyHC‐slow fibers, normalization of Pax7 levels, increased grip strength, decline in fibrosis, and reduction in scoliosis in adult Myh3 knockout mice. The gene discussed is PAX7; the disease is scoliosis.