This family of proteins is found in eukaryotes, where members are expressed at high levels in the brain, liver kidney and Ewing tumour cell lines. Proteins in this family are typically between 648 and 898 amino acids in length.

1: Structure and function of ETAA16: a novel cell surface antigen in Ewing's tumours. Borowski A, Dirksen U, Lixin L, Shi RL, Gobel U, Schneider EM; Cancer Immunol Immunother. 2006;55:363-374. PMID:16003559