GDF15 and neoplasm: In gene expression profiling studies, among the differentially expressed genes between MM-MSCs and HD-MSCs, a large proportion of genes were involved in tumor-microenvironmental cross-talk, and were implicated in tumor-support (e.g., IL-6, IL-1β, AREG, GDF15), angiogenesis (e.g., ANGPTL4, PAI-1), and contribution to bone disease (e.g., NPR3, WISP1).