The invention generally relates to an immunomodulatory protein and a chemotherapeutic agent for simultaneous, contemporaneous or sequential use in the treatment of diseases, more particularly of proliferative diseases, still more particularly of cancer(s), to a combination of an FIP and a chemotherapeutic agent, as well as to the medical and biotechnological applications thereof, more particularly in the field of the treatment of diseases, more particularly of proliferative diseases, still more particularly of cancer(s).