AADACL4 is a 407 amino acid single-pass type II membrane protein belonging to the 'GDXG' lipolytic enzyme family. Integral to the cell membrane, AADACL4 participates in carboxylesterase and hydrolase activities and is encoded by a gene that maps to human chromosome 1p36.22. Chromosome 1, the largest human chromosome, makes up 8% of the human genome and contains about 260 million base pairs, which encode 3,000 genes. Chromosome 1 houses a large number of disease-associated genes, including those that are involved in familial adenomatous polyposis, Stickler syndrome, Parkinson’s disease, Gaucher disease, schizophrenia and Usher syndrome. Aberrations in chromosome 1 are found in a variety of cancers, including head and neck cancer, malignant melanoma and multiple myeloma.