INPP4B and Miyoshi myopathy: To further investigate how INPP4B influences MM malignancy, we successfully ectopically overexpressed INPP4B and silenced INPP4B in LP-1, RPMI 8226, and MM.1S cells, respectively (Figures 3A, B), after the optimized time point of overexpression and knockdown of INPP4B expression were confirmed (Supplementary Figures S1A, B).