diff --git a/mutalyzer/Retriever.py b/mutalyzer/Retriever.py
index 48750a9322a6d3c463e642467285b3651d6d3647..0cb76ef32c40da361120cc2f14692f7a4ae11544 100644
--- a/mutalyzer/Retriever.py
+++ b/mutalyzer/Retriever.py
@@ -585,7 +585,7 @@ class GenBankRetriever(Retriever):
                                         'Could not get mapping information for gene %s.' % gene)
                 return None
 
-            if summary[0]["NomenclatureSymbol"] == gene : # Found it.
+            if summary[0]["NomenclatureSymbol"].lower() == gene.lower() : # Found it.
                 if not summary[0]["GenomicInfo"] :
                     self._output.addMessage(__file__, 4, "ENOMAPPING",
                         "No mapping information found for gene %s." % gene)