The invention provides a method of treating a patient having target cells that express FcγRIIb, the method comprising administering (i) an antibody molecule that specifically binds a surface antigen of the target cell, which antibody molecule has an Fc domain capable of binding FcγRIIb； in combination with (ii) an agent that prevents or reduces binding between the Fc domain of the antibody molecule and FcγRIIb； characterized in that the patient is selected on the basis that their target cells express an elevated level of FcγRIIb.
