EBPL is expressed as a homodimer with high levels found in liver, lung and kidney. As a transmembrane protein embedded on the endoplasmic reticulum, EBPL may function as a cholestenol delta-isomerase. The gene encoding EBPL is found on human chromosome 13. Comprising nearly 4% of the human genome, chromosome 13 contains around 114 million base pairs and encodes over 400 genes. Chromosome 13 houses key tumor suppressor genes, including BRCA2 and RB1, which are associated with breast cancer susceptibility and retinoblastoma, respectively. Trisomy 13, also known as Patau syndrome, is deadly and the few who survive past one year suffer from permanent neurologic defects, difficulty eating and vulnerability to serious respiratory infections.