[...] This priority refers to the need for deeper knowledge on the existing barriers to the interoperability of systems across healthcare systems, as well as across health domains and countries (e.g. existing national infrastructures may not be yet prepared to respond to interoperability requirements). Standardisation plays an emerging role on enabling interoperability, especially regarding cross-European interoperable frameworks. Therefore, focus should be placed on the identification of data transmission details and on the technical requirements needed, so proper (and hopefully common) standards can be defined and implemented.