One of the concerns that led to the introduction of Article 4(2) TEU was the growing interference of EU law into areas traditionally reserved to the Member States. In particular, Article 4(2) TEU was seen as a way to better shield matters of ‘retained competences’, where EU institutions have not been conferred legislative competences, and to possibly create no-go areas for EU law. Yet, this article argues that in practice, the national identity clause has not worked as a limit to EU competences and the scope of EU law. The case law of the Court of Justice in the decade after the entry into force of the Lisbon Treaty, and in particular a set of recent decisions in sensitive areas such as religion, family and nationality analysed in this article, allow to conclude that reliance on Article 4(2) TEU does not limit the scope of application of EU law, though it may contribute to reach results that show deference to national preferences and leave room for national diversity. The article thus suggests a weaker reading of the national identity clause: not as a fully blown limit to EU competence, but as one of the many clauses that stand for, and guarantee, national diversity.