The WDNM1 gene product is a novel member of the 'four-disulphide core' family of proteins.

It has been previously demonstrated that the WDNM1 gene is downregulated in metastatic rat mammary adenocarcinomas. Detailed analysis of the structure of WDNM1 mRNA reveals the presence of two transcripts generated by alternative splicing of a single exon. The unspliced version possesses an in-frame termination codon which encodes a predicted protein of 18 amino acids. The spliced version encodes a predicted protein of 60 amino acids which exhibits strong homology to a family of proteins possessing a conserved arrangement of cysteine residues. This family includes several proteinase inhibitors suggesting that WDNM1 could encode a product with proteinase inhibiting capacity. Possible modulation in the level of this protein product could be related to overall proteinase activity of specific tumour cells which, in turn, could influence the invasive and metastatic potential of such cell populations.