Dear Participants Here are a few updates regarding the data of the challenge: * As some of you noticed, data of **subchallenge 1** had _3 trees_ with small mislabeling of _cell ids_ in ground truth of the training set and of one tree in the test set, so please **download the data again**! This has been fixed. * Test set for **subchallenge 3** should be ready in about a week, once we have it we will update on the date for submissions to the leaderboard. * Please remember that all **trees you submit need to be rooted** given that one of the scores we are using is triplets. Indicate it by adding "root", please no uppercase. It should be pretty obvious which cell is the root. * If you missed the webinar you can see the [recording](https://zoom.us/recording/play/LdnHyZuxYGtgHHDMVLR1Qjl3Ims8LtOLI9rZpcpKk8RQ3Yf7YHrcc1hmHYzSb5Cz?startTime=1572281997000) and [slides](https://www.synapse.org/#!Synapse:syn21071995). Thanks for your participation, Challenge Organizers