In support of this, the ability of preosteoblasts to promote myeloma cell viability was reduced in the presence of excess MMP-7 expressed by the host cells, highlighting the tumour-suppressive effect of MMP-7 in the myeloma-bone microenvironment and suggesting that the effect may be mediated at least in part by a substrate expressed by osteoblasts. Here, MMP7 is linked to plasma cell myeloma.