The Delta-like 1 homolog (DLK1) is a transmembrane protein containing six epidermal growth factor repeats. It is involved in the differentiation of several cell types, including adipocytes and is also thoμght to be a tumor suppressor. The DLK1 gene is one of several imprinted genes located in a region on chromosome 14q32; certain mutations in this imprinted region can cause phenotypes similar to maternal and paternal uniparental disomy of chromosome 14 (UPD14). DLK1 is expressed from the paternal allele; a polymorphism within this gene has been associated with child and adolescent obesity.