EGFL6 encodes a member of the epidermal growth factor (EGF) repeat superfamily.The predicted 553-amino acid EGFL6 protein has a putative N-terminal signal peptide, which suggests that it is secreted; an EGF repeat region containing 4 complete EGF-like repeats and 1 partial EGF-like repeat; an integrin association motif (RGD); 2 potential N-glycosylation sites; and a potential tyrosine phosphorylation site. Northern blot analysis of a variety of normal human tissues detected an approximately 2.4-kb EGFL6 transcript only in placenta. Among the cancer tissues tested, EGFL6 expression was found only in meningioma tumors. Screening-by-hybridization analysis of various cDNA libraries indicated EGFL6 expression in lung tumor, fetal lung, fetal skin, fetal umbilical cord, fetal liver/spleen, and placenta, but not in normal adult tissues, including lung.