diff --git a/scrna/cellassign_tutorial.ipynb b/scrna/cellassign_tutorial.ipynb
index e54bd77..8970bd9 100644
--- a/scrna/cellassign_tutorial.ipynb
+++ b/scrna/cellassign_tutorial.ipynb
@@ -137,7 +137,6 @@
     "\n",
     "import matplotlib.pyplot as plt\n",
     "import pandas as pd\n",
-    "import numpy as np\n",
     "import scanpy as sc\n",
     "import scvi\n",
     "import seaborn as sns\n",
@@ -262,10 +261,10 @@
     }
    ],
    "source": [
-    "os.system(\"wget -q https://ndownloader.figshare.com/files/27458798 -O \"+sce_follicular_path)\n",
-    "os.system(\"wget -q https://ndownloader.figshare.com/files/27458822 -O \"+sce_hgsc_path)\n",
-    "os.system(\"wget -q https://ndownloader.figshare.com/files/27458828 -O \"+hgsc_celltype_path)\n",
-    "os.system(\"wget -q https://ndownloader.figshare.com/files/27458831 -O \"+fl_celltype_path)"
+    "os.system(\"wget -q https://ndownloader.figshare.com/files/27458798 -O \" + sce_follicular_path)\n",
+    "os.system(\"wget -q https://ndownloader.figshare.com/files/27458822 -O \" + sce_hgsc_path)\n",
+    "os.system(\"wget -q https://ndownloader.figshare.com/files/27458828 -O \" + hgsc_celltype_path)\n",
+    "os.system(\"wget -q https://ndownloader.figshare.com/files/27458831 -O \" + fl_celltype_path)"
    ]
   },
   {