SLAMF7 is a protein that in humans is encoded by SLAMF7 gene. It is a robust marker of normal plasma cells and malignant plasma cells in multiple myeloma. In contrast to CD138 (the traditional plasma cell marker), CD319/SLAMF7 is much more stable and allows robust isolation of malignant plasma cells from delayed or even cryopreserved samples. Elotuzumab is an antibody that targets this protein.