RRBP1 and Miyoshi myopathy: Our results indicate that both Hes and Nar significantly inhibited the growth of PI-sensitive (AMO and NCI-H929) or resistant (AMO-BZB, H929 BZB, H929-CFZ) MM cell lines in a dose-dependent manner (Fig. 2B; IC50 values are reported in Additional file 1: Fig. S5); as previously reported, no cytotoxic effect was observed on healthy PBMCs (data not shown) [43], suggesting a favorable therapeutic window.