IL6 and plasma cell myeloma: Various global clinical trials, series, and pilot studies of off-label use of siltuximab and tocilizumab provide strong indications [61] that the anti-IL-6 therapy may be used for the treatment of blood cancers such as multiple myeloma [62] and leukemia [63] and of solid tumors such as prostate cancer [64], breast cancer [65], and ovarian cancer [66].