404. That’s an error.

The requested URL /bookmarks/mark?op=add&bkmk=http%3A//www.genetics.org/content/113/2/469&title=MAIZE%20MITOCHONDRIAL%20PLASMID%20S-1%20SEQUENCES%20SHARE%20HOMOLOGY%20WITH%20CHLOROPLAST%20GENE%20psbA was not found on this server. That’s all we know.