Inhibiting myostatin in the KIActa1H40Y nemaline myopathy mouse line using an activin type IIB receptor monoclonal antibody (ActRIIB-mFc; Acceleron Pharma, Cambridge, MA, USA) extended the usually shortened lifespan of male mice but did not improve other disease features50. The gene discussed is ACVR2B; the disease is nemaline myopathy.