IL6 and Castleman disease: IL-6 is abundant in plasma and tissues in several chronic diseases, like rheumatoid arthritis [9,10], Castleman’s disease [11], and brain tumors such as glioblastoma etc. For this reason, finding the modes of regulating IL-6 expression, protein abundance, and signal transduction is critical to help prevent and reduce severity and duration of pathological state implicating excessively high IL-6 concentrations.