The signaling pathways are mediated by growth factors (EGF, HGF, TGFB3, BMP4), cytokines (TNF, SLIT2) and specific receptors (CD3E, CD28, FCGR3B, CSF2R), suggesting greater influence of activated fibroblasts in MM compared to the condition of MGUS. This evidence concerns the gene CD28 and Miyoshi myopathy.