Direct effect is not explicitly stated in any of the EU Treaties. The principle of direct effect was first established by the Court of Justice of the European Union (CJEU) in "Van Gend en Loos v. Nederlandse Administratie der Belastingen". Direct effect has subsequently been loosened in its application to treaty articles and the ECJ has expanded the principle, holding that it is capable of applying to virtually all of the possible forms of EU legislation, the most important of which are regulations, and in certain circumstances to directives.