IL-6 does not inhibit 8Cl-cAMP or 8Cl-AD activity. MM.1S (A) and MM.1R (B) cells are treated for 5 days with control medium only, dexamethasone (1 μmol/L), 3 μmol/L 8Cl-cAMP, or 3 μmol/L 8Cl-AD in the presence (light bars) or absence (dark bars) of 500 pg/mL IL-6. Cell number is assayed and presented as described in Materials and Methods.