The absence of dystrophin produces a dysfunctional regulation of intracellular Ca2+ in skeletal muscle of DMD patients (Lopez et al., 1987) and in dystrophin-deficient mdx mice, one of the most frequently used animal models of DMD (Allen et al., 2010a; Altamirano et al., 2014) as well as in cardiac muscle (Mijares et al., 2014; Lopez et al., 2017). The gene discussed is DMD; the disease is Duchenne muscular dystrophy.