Novel peptidic or peptidomimetic agents or small molecules for modulating the biological effect of a chemokine. According to the present invention, the therapeutic agents preferably are endowed with the capacity to bind to certain chemokines in order to modulate the biological interaction between the target ligand, chemokine, and the respective target receptor, chemokine receptor. These peptides may be described as agonist ligands or antagonists. Next, preferably certain peptides share consensus sequences are described which characterize the families or categories of these modulator peptides.