In addition, MUC20 overexpression via transfection with a lentiviral vector carrying MUC20 (Supplementary Figure S4A) enhanced the inhibitory effect of PI treatment on PI-resistant KAS-6/1 and U266 cell proliferation (Fig. 3A), suggesting that MUC20 alleviates PI resistance in MM cells. This evidence concerns the gene MUC20 and Miyoshi myopathy.