Abstract: Compositions of matter and methods for expressing a polypeptide are provided. In one aspect, a gene construct is provided that comprises an enhancer comprising particular elements or combinations of elements from the immunoglobulin &kgr; locus, the immunoglobulin heavy chain &mgr; locus, and the immunoglobulin &lgr; locus, and a promoter and polyadenylation site linked to a nucleotide sequence encoding a polypeptide from a select group. Cells comprising the gene construct, processes for producing such cells, and processes for producing the polypeptide encoded by the gene construct from such cells are also provided.