Do I need to apply a mirror modifier before exporting to Unity?

I exported my character without applying mirror modifier and it seems it works well in both situation. Will it make any differences?

• Exporting in formats like .dae, .fbx, .obj has Apply Modifiers option, and in some cases it's checked by default. In this case the modifier has been applied automatically (even without your action). If it hadn't I think you would have noticed that. – Mr Zak Sep 9 '15 at 16:19
• ok, you can add your comment as answer. thanks. – user3160302 Sep 11 '15 at 11:24