IL6 and neoplasm: Both compartments have been shown to interact with MM cells and contribute toward tumor growth and disease pathology.[5], [6] Interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), and insulin-like growth factor 1 are secreted by BM SCs, osteoclasts, osteoblasts, and/or MM cells themselves and each of these soluble factors stimulates MM cell growth and/or survival.