You created a Track Collection that has expired and been removed. Track Collections expire 48 hours after their last use. Save your session to preserve collections long-term and to allow sharing.
Track data hubs are collections of external tracks that can be added to the UCSC Genome Browser. Click Connect to attach a hub and redirect to the assembly gateway page. Hub tracks will then show up in the hub's own blue bar track group under the browser graphic. For more information, including where to host your track hub, see our User's Guide.
Track Hubs are created and maintained by external sources. UCSC is not responsible for their content.
Create your own hub
For information on making track hubs, see the following pages:
You may also contact us if you have any issues or questions on hub development.
Check a hub for errors
Load Example URL
Use the URL bar above to check a hub for errors. This will validate the hub's configuration files, including hub.txt, genomes.txt and trackDb.txt. It will also present a hierarchical tree of tracks with any errors in red. A hub with no errors still shows the tree which can be used to explore the track hierarchy. Hub error checking will always refresh the files and never use our remote file cache (see below).
Enable Genome Browser debugging modes
These apply to all connected hubs. By default, caching is activated and track load times are not shown, but you can change these settings while developing your hub: