404. That’s an error.

The requested URL /bookmarks/mark?op=add&bkmk=https%3A//mcb.asm.org/content/14/12/8315&title=Distinct%20residues%20of%20human%20p53%20implicated%20in%20binding%20to%20DNA%2C%20simian%20virus%2040%20large%20T%20antigen%2C%2053BP1%2C%20and%2053BP2. was not found on this server. That’s all we know.