fix typo

app.py

@@ -45,7 +45,7 @@ top_coexp_hits.reset_index()
 
 st.download_button(
     label="Download data as TSV",
-    data = top_coexp-hits.to_csv(sep ='\t').encode('utf-8'),
+    data = top_coexp_hits.to_csv(sep ='\t').encode('utf-8'),
     file_name= f"top_coexp_hits_{gene_id}.tsv",
     mime="text/csv")