The present invention provides a recombinant protein or a derivative thereof, wherein the recombinant protein has an amino acid sequence of the N-terminal portion of CC chemokine receptor 4 (CCR4). The invention also provides the use of the recombinant protein or a derivative thereof for treating or preventing a disease or condition associated with CCR4 signaling, such as an allergic disease, inflammatory enteritis, psoriasis, an inflammatory skin disease, vasculitis, spondyloarthropathy, scleroderma, asthma, a respiratory allergic disease, an autoimmune disease, graft rejection, leukemia, lymphoma, a blood-borne cancer, a disease requiring inhibition of undesirable inflammation, and a cancer.