A Secure and Interoperable Big Data Platform for AI-Driven Healthcare Solutions: Insights From the GATEKEEPER Project. - Christian Temporale; Edmondo De Salvo; Eugenio Gaeta; Miguel Rujas; Laura Lopez-Perez; Muhammad Salman Haleem; Vassilios Aidonis; Eleni I. Georga; Dimitrios I. Fotiadis; Leandro Pecchia; Giuseppe Fico (IEEE Access, 2026)