The PDZD2 gene encodes a protein that contains six PDZ domains.  However, proteolytic cleavage mediated by caspase results in a secreted peptide containing only two of these PDZ domains.  While the function of PDZD2 is still not fully understood, it is known that PDZ domains frequently bind to the C-termini of transmembrane receptors or ion channels.  Hence, it is speculated that the protein could be involved in intracellular signaling.

The gene is found to be upregulated in primary prostate tumors and evidence strongly suggests that accumulation of the protein may be associated with the initiation of prostate tumorigenesis.  Recent studies have also shown a possible link between the gene and other cancers, particularly with gastric and renal cell carcinoma.

The PDZD2 gene, located on the short arm of chromosome 5, is approximately 471 kb long with a coding sequence consisting of 30 exons.  The gene is found to be overexpressed in the plasma, frontal cortex, placenta and heart.  Alternative splicing of the gene results in transcripts that encode two different isoforms of the protein.  Isoform 1 of the PDZD2 protein is made up of 2839 amino acids and is about 301 kDa in size.  Isoform 2 of protein, which is only 280 kDa in size, is found to be expressed in the prostate.