It must be borne in mind that if the institution concerned decides to refuse access to a document which it has been asked to disclose, it must, in principle, explain how disclosure of that document could specifically and actually undermine the interest protected by the exception — among those provided for in Article 4 of Regulation No 1049/2001 — upon which it is relying (judgments in Sweden v MyTravel and Commission, cited in paragraph 35 above, EU:C:2011:496, paragraph 76, and of 28 March 2012 in Egan and Hackett v Parliament, T‑190/10, EU:T:2012:165, paragraph 90). Such an explanation cannot therefore consist of a mere assertion that access to certain documents would undermine privacy within the meaning of Article 4(1)(b) of Regulation No 1049/2001 (judgment in Egan and Hackett v Parliament, EU:T:2012:165, paragraph 91).