EGF-like domains are believed to play a critical role in a number of extracellular events, including cell adhesion and receptor-ligand interactions. Proteins with EGF-like domains often consist of more than 1,000 amino acids, have multiple copies of the EGF-like domain, and contain additional domains known to be involved in specific protein-protein interactions. To identify proteins containing EGF-like domains, Nakayama et al. (1998) searched a database of long cDNA sequences randomly selected from a human brain cDNA library for those that encode an EGF-like motif. They identified several partial cDNAs encoding novel proteins with EGF-like domains, such as EGFL4, which they named MEGF8
. The predicted partial EGFL4 protein has a laminin-type EGF-like domain, 5 EGF-like domains, and a transmembrane domain.