IL6 and Miyoshi myopathy: Another group has also suggested that miR-21 as a key oncomiR in MM [29].Our results show that BB down-regulates miR-21 levels in MM cell lines (RPMI-8266 and U226) (Figure 2A), but does not affect miR-21 levels in IL6-independent human myeloid leukemia cells (HL60, NB4, and K562 cell lines; data not shown).