The glandular kallikrein gene family comprises 25-30 highly homologous genes that encode specific proteases involved in the processing of biologically active peptides. In the mouse all the members of this family are closely linked on chromosome 7. The 9.5-kilobase nucleotide sequence of a mouse genomic clone contains one complete kallikrein gene (mGK-1), which is expressed in the male mouse submaxillary gland, and the 3' end of another (mGK-2). Differences in the coding potential of these genes and the amino acid sequences of other known kallikreins seem to be functionally related to the substrate specificity of the different enzymes.