The expression analysis of miR-221/222 in our screening cohort (n = 141) highlighted the strong correlation between miR-221 and miR-222 levels (Pearson test; r = 0.949, p < 0.001; Fig. 3A), unveiling their potent co-regulation in CD138+ plasma cells, allowing us to study the clinical value of miR-221/222 cluster in MM outcome (Figs. 3, 4). The gene discussed is SDC1; the disease is Miyoshi myopathy.