Immunogen sequence: PGVWAFHIGS TSPLDNVRPA AVGDLSAAHS SVPLGRSFSH ATALESDYNE DNLDYYDVNE EEAEYLPGEP EEALNGHSSI DVSFQSKVDT KP. Basement membranes, which are composed of type IV collagens, laminins, perlecan, and nidogen, are thin pericellular protein matrice