Structure of CD97 soluble proteins. Constructs encompassing the extracellular domain of CD97 up to the natural proteolysis processing site at amino acid 531 are designated full length (FL). Isoforms containing 3 (E/1,2,5) or 5 (E/1-5) EGF-like repeats, an RGD motif, and mucin stalk, as well as RGD to RGE and various deletion mutants, were used in this study.