We showed that FAC-treatment promotes M2-like monocytes with CD206highCD86lowHLA-DRlow phenotype together with a downregulation of pro-inflammatory cytokines (IL-6, CCL2, TNFα mRNA) and increased expression of anti-inflammatory markers (ARG1 and TGFB1), thus suggesting the establishment of an iron-mediated immune suppressive tumor microenvironment favoring MM cells growth and survival. Here, ARG1 is linked to Miyoshi myopathy.