Among all components of SRP, SRP54 is considered the main antigenic target of anti-SRP antibodies (Targoff et al., 1990) with antibodies against SRP54 found in patients with severe myopathies and Lupus-type autoimmune diseases (Miller et al., 2002; Hengstman et al., 2006). The gene discussed is UCN2; the disease is myopathy.