Inactivation of Xin in chick embryos led to looping defects, abnormal beating behavior and edema (Wang et al., 1999), while Xin-deficient mice display myopathy, impaired contractility, and attenuated muscle repair (Al-Sajee et al., 2015), which indicating a crucial role in heart development and cardiac disease. The gene discussed is XIRP1; the disease is myopathy.