<p>Introduction: Multiple Myeloma (MM) is an incurable hematological malignancy affecting plasma cells marked by highly heterogeneous survival rate. Relapse is a significant impediment to the successful treatment of MM clinically. One of the main causes for relapse in MM is the development of multidrug resistance (MDR) to cancer chemotherapy. Currently, risk stratification to MM sub-groups and categorization of complete response to therapy are assessed based on molecular, cytogenetic markers using bone marrow biopsy as available systemic markers are incompetent in this regard. We are exploring the clinical significance of our recent in vitro and in vivo findings of a novel non-genetic basis to MDR whereby tiny vesicles called microparticles (MPs) shed from cancer cell's surface transfer MDR phenotype intercellularly. Microparticles isolated from the peripheral blood of patients who suffer from Multiple Myeloma will be phenotyped for resistance, adhesion and dissemination markers. Subsequently, these parameters will be correlated clinically to assess whether these characteristics are predictive of treatment outcome.</p>