To identify which among various cytokines are retained with high concentration in the serum of multiple myeloma patients, 8 cytokine (IL-2, IL-4, IL-6, IL-10, IL-17, TNFα, TGFβ_1, and IFNγ) levels were measured using 45 bone marrow aspirate samples of multiple myeloma patients (Table 1). Here, IL6 is linked to plasma cell myeloma.