EGFL4 (epidermal growth factor-like protein 4), also known as MEGF8 (multiple epidermal growth factor-like domains protein 8) or C19orf49, is a 2,845 amino acid single-pass type I membrane protein. EGFL4 contains 2 CUB domains, 5 EGF-like domains, 12 Kelch repeats, 4 laminin EGF-like domains and 7 PSI domains. Existing as two alternatively spliced isoforms, the gene encoding EGFL4 maps to human chromosome 19q13.2. Chromosome 19 consists of approximately 63 million bases, makes up over 2% of human genomic DNA, and is recognized for having the greatest gene density of the human chromosomes. It is the genetic home for a number of immunoglobulin superfamily members including the killer cell and leukocyte Ig-like receptors.