Data Lake is an EU-funded start-up creating a global medical data donation system based on blockchain technology, with privacy and informed consent as fundamental pillars. The system empowers people to give or revoke consent to the usage of their medical data in a safe, easy and private way, while providing large datasets that will revolutionize scientific research and medical studies. It also incentivizes and rewards the participation of stakeholders in the data donation system, giving donors an on-ramp to the enormous medical data economy, and allowing hospitals to offset the costly storage of medical data.