Chemokines are a group of peptides of low molecular weight that induce the chemotaxis of different leukocyte subtypes . The major function of chemokines is the induction of leukocyte migration to inflammation sites, but they also play a role in tumoral growth, in angiogenesis and in organ sclerosis . At the present more than 50 chemokines have been described, which can be classified in 4 major families on the basis of the position of the cysteine residues in their NH2 terminal portion . So far, only two of these families have been extensively studied and characterized. They are CC and CXC (target of our interest), chemokines which are defined on the fact that between two cysteine residues another aminoacid is inserted.