GDE4 is a 314 amino acid cytoplasmic and multi-pass membrane protein that belongs to the glycerophosphoryl diester phosphodiesterase family. Expressed in small intestine, placenta, kidney, ovary, thymus, pancreas, spleen, liver and peripheral blood leukocytes, GDE4 contains one GDPD domain and exists as three alternatively spliced isoforms. GDE4 is encoded by a gene that maps to human chromosome 17, which comprises over 2.5% of the human genome and encodes over 1,200 genes. Two key tumor suppressor genes are associated with chromosome 17, namely, p53 and BRCA1.