C4A and Miyoshi myopathy: Furthermore, <i>in vitro</i> experiments validated the positive regulatory effects of ELK3 on plasma cell proliferation, migration, and cell viability in MM.<h4>Conclusion</h4>In summary, this study, based on scRNA-seq analysis, identified a C4 <i>TTN+</i> plasma cell subtype potentially associated with <i>ELK3</i>.