Marie Skłodowska-Curie Innovative Training Networks (ITN-ETN) European Training Networks (ETN) ETNs are multi-partner research training networks and must be composed of at least three beneficiaries established in at least three different EU Member States or Associated Countries. Above this minimum, the participation of other organisations, including international organisations and those from Other Third Countries, is possible under the conditions provided by the Horizon 2020 Rules for Participation. Although there is no pre-defined size for these multi-partner networks, it is strongly recommended to keep the size of the consortium between 6 and 10 beneficiaries. It is expected that beneficiaries will be drawn from the academic and non-academic sectors and that ETN proposals will offer intersectoral and interdisciplinary research training as well as high-quality supervision arrangements. Each beneficiary must recruit and host at least one ESR.