However, even if MM MSCs are able to correctly support hematopoiesis, we have shown that these cells retain a pathologic signature, including better support of MM cell line growth and a higher expression of IL-6 and GDF15, than do HD MSCs, as well as a differential expression of 145 genes involved in osteogenic differentiation or tumor growth [13, 14]. This evidence concerns the gene GDF15 and neoplasm.