Christian iconographic mosaics can be uncovered, but often at the expense of important and historic Islamic art. Restorers have attempted to maintain a balance between both Christian and Islamic cultures. In particular, much controversy rests upon whether the Islamic calligraphy on the dome of the cathedral should be removed, in order to permit the underlying Pantocrator mosaic of Christ as Master of the World, to be exhibited (assuming the mosaic still exists).[206]