Myeloma (MM) is an incurable blood cancer characterized by the development of devastating bone disease. We identified a protein named C/EBPβ as a critical factor, regulating growth and expansion of MM cells. In our grant we hypothesize that C/EBPβ plays a critical role in MM cell growth/survival and interacts with the bone marrow microenvironment, in turn resulting in further induction of MM and MM bone disease. The confirmation of our hypothesis will provide a novel treatment approach of simultaneously targeting the MM cancer cell and the bone resorbing cells, thereby preventing further destruction of the bone.