On September 6, 2023, the kickoff meeting of the EOSC4Cancer network of cancer data support professionals took place. In the context of the WP5 “Training and capacity building for key national and international stakeholders”, our aim is to unlock the expertise in handling cancer related data both within and outside of the EOSC4Cancer consortium. To this end, in Task5.3 we will bring together a network of key cancer data support professionals (a.o. data stewards), coming from within the EOSC4Cancer member institutes, the respective RIs, relevant national initiatives and competency centers. On June 19 2023, we presented the proposed setup and activities of the network in a webinar and you can find the slides here: https://doi.org/10.5281/zenodo.8073707 . The network of cancer data support professionals is foreseen to a) share expertise, best practices, training resources, challenges b) work together on identified tasks (a.o. RDMkit Cancer view pages) and c) align and connect to already existing networks of cancer data support professionals.