404. That’s an error.
The requested URL /bookmarks/mark?op=add&bkmk=http%3A//www.biorxiv.org/content/early/2016/04/28/022616&title=A%20profile-based%20method%20for%20identifying%20functional%20divergence%20of%20orthologous%20genes%20in%20bacterial%20genomes
was not found on this server. That’s all we know.