Several literature data are available about the relations between RDW and inflammatory markers, such as erythrocyte sedimentation ratio and C-reactive protein21 but, in MM, is more plausible than the variation of RDW may mainly depend on high circulating levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and hepcidin22–24. Here, TNF is linked to Miyoshi myopathy.