PRMT5 and Miyoshi myopathy: To verify whether PRMT5 inhibition could indeed selectively affect MTAP‐deficient MM cell growth, we stably transduced with lentiviral vectors expressing shRNAs against PRMT5 (shPRMT5) or a non‐targeting (NT) control shRNA, the MTAP‐negative MM cells, NCI‐H2452, MMB‐1 and IST‐Mes2, the MTAP‐positive MM cells, MPP 89, and the non‐tumour mesothelial cells, MeT‐5A.