In addition to the autocrine effect of myeloma cells on osteoclasts and osteoblasts, their modulation of the proximal bone marrow microenvironment also results in the further release of RANKL, macrophage colony-stimulating factor (MCSF), interleukin-6 (IL6), and TNF-α from bone marrow stromal cells [98,99,100] or osteoblast inhibitory factors like sclerostin from osteocytes [26,28,101,102,103], among others. This evidence concerns the gene SOST and plasma cell myeloma.