Everyday, new deep learning algorithms are trained to solve specific tasks, such as medical images classification. What if we could share and connect those algorithms and create the conditions for a cross-fertilization between these powerful artificial intelligence systems ? In this talk, we will discuss the fundamental role of transfer learning to foster the emergence of collaborative artificial intelligence and show how it can bring the power of big-data-trained deep learning algorithms into the world of medical not-so-big data. As an illustration, we will present a new platform for medical image recognition based on deep transfer learning and collaborative AI.