First clinical application of murine anti IL-6 monoclonal antibody was trialed in a patient with multiple myeloma (MM); it improved tumor burden and suppressed inflammatory acute phase responses, but it led to accumulation of IL-6- antibody immune complexes in the blood, preventing elimination of IL-6 and creating high level of IL-6, highlighting the need for IL-6 receptor blockade instead (58). This evidence concerns the gene IL6 and plasma cell myeloma.