Granulins (grns) or epithelins (epis) are peptides with molecular masses of approx. 6 kDa that modulate the growth of cells. The precursor for the grns/epis, which might itself be biologically active, is a secreted glycoprotein containing multiple repeats of the grn/epi motif. Grn/epi mRNA occurs widely in vivo, particularly in tissues rich in epithelial and haematopoietic cells. To understand better the role of the gene products for grn/epi it is important to determine the patterns of grn/epi gene expression and how this is regulated. To assist in this we have obtained the 5' sequence of the human grn/epi gene, and using chimaeras of the grn/epi -5' sequence and the chloramphenicol acetyltransferase gene we have shown a strong promoter activity associated with the 5' sequence of the human grn/epi gene. We have further delineated regions of the 5' sequence that confer high-level expression on the chimaeric gene.