The flIMAGIN3D project will create a research training network on the biomedical applications of 3D fluorescent lifetime imaging microscopy (FLIM). The project aims to recruit 10 doctoral candidates for the creation of robust, user friendly, innovative FLIM-based platforms for a broad range of biomedical applications. The training network will cover the essential theoretical foundation of FLIM and, through the individual projects, address the existing knowledge gap in photonics applications in biology. The flIMAGIN3D early career researchers will develop FLIM platforms capable of delivering new information to understand biology in disease, differentiation, development and interventions at a high resolution.