Judgment_paragraph 20 · Alessandra Venturini v ASL Varese and Others Maria Rosa Gramegna v ASL Lodi and Others and Anna Muzzio v ASL Pavia and Others (C-159/12, C-160/12, C-161/12)

20Secondly, it should be recalled that the need to provide an interpretation of EU law which will be of use to the national court requires that the national court define the factual and legal context of its questions or, at the very least, that it explain the factual circumstances on which those questions are based. Those requirements are of particular importance in the area of competition, where the factual and legal situations are often complex (see, inter alia, Attanasio Group, paragraph 32, and Joined Cases C‑357/10 to C‑359/10 Duomo Gpa and Others [2012] ECR, paragraph 22).