The present invention relates to a metallic oxide film which exhibits a high hardness and is good in terms of the transparency, and which exhibits a hydrophilic property, a defogging and dirtproof property and a self-cleaning property over a long period of time, a production process for the same, and a hydrophilic mirror comprising this hydrophilic metallic oxide film. The invention also provides a family of monoclonal antibodies that bind to antigen JAM-3, methods of diagnosing and treating various human cancers and diseases that express JAM-3. In a second process, a 5,7,3\u2032,4\u2032-tetra-O-protected or preferably penta-O-protected-epicatechin or -catechin monomer or oligomer is reacted with a tetra-O-protected or preferably penta-O-protected-epicatechin or -catechin monomer having a thio activating group at the C-4 position; the coupling is carried out in the presence of silver tetrafluoroborate.