AK155 is a recently discovered cytokine distantly related to IL-10. Its gene is located on chromosome 12q15, a region that is likely to harbour susceptibility genes for autoimmune and allergic diseases. We provide here identification and characterization of two microsatellite polymorphisms at the AK155 locus, i.e. D12S2511 and D12S2510. The first is located in the third intron and the second in the 3' region of the gene. Both might be useful as markers in association or linkage studies of polygenic inflammatory or allergic diseases. No association with multiple sclerosis was found for each of these markers by means of the transmission disequilibrium test in an extended number of Sardinian simplex families.