The CC type chemokines belong to a family of polypeptides which have proven to be mediators of immune reactions, and they have recently attracted attention due to their antiviral activity with respect to HIV. The cloning and molecular characterization of a human tandem gene is disclosed which contains the closely linked coding regions for two new CC type chemokines the sequences of which are highly homologous with that of MIP-1&agr;. The transcription of the tandem gene leads to a bicistronic mature transcript which contains the non-overlapping open reading frames for the recently described factor HCC-1 and an as yet unknown CC type chemokine, designated as CC-2. Moreover, alternative splicing of the primary transcript yields at least one additional CC type chemokine, cytokine CC-3. Two functional promoter regions were identified within the tandem gene. The disclosed data provide some basic knowledge about the structure and expression of the new human CC-2/HCC-1 tandem gene and describe a mechanism according to which the coexpression of closely linked genes could be regulated in higher eucaryotes.