Novel biomarkers in plasma cell disorders

The invention relates to novel biomarkers for plasma cell disorders, such as multiple myeloma,and in particular the use of microRNAs as diagnostic and prognostic markers in assyas for detecting such disorders. The invention also relates to methods of determining the efficacy of treating such a plasma cell disorder with a therapeutic agent and kits for carrying out the assays and methods. The assays are qualitative and/or quantitative and are adaptable to large-scale screening and clinical trials.