diff --git a/cellarium/cas/visualization/circular_tree_plot_umap_dash_app/app.py b/cellarium/cas/visualization/circular_tree_plot_umap_dash_app/app.py
index dd21820..2b78e29 100644
--- a/cellarium/cas/visualization/circular_tree_plot_umap_dash_app/app.py
+++ b/cellarium/cas/visualization/circular_tree_plot_umap_dash_app/app.py
@@ -1,4 +1,3 @@
-import logging
 import os
 import tempfile
 import typing as t