Chromatin packages a few meters of DNA into a nucleus measuring a few microns. This tight folding occurs by assembling DNA with histones into so-called nucleosomes, thus ensuring the mechanical stability of our genome. On the flipside, this makes nucleosomes a formidable obstacle to the machines that read, copy or repair its DNA message. One of the fundamental questions in biology is to understand how nucleosome structure is established, maintained and manipulated. Our Marie Curie Initial Training Network will carry out multidisciplinary, collaborative research projects focused on deciphering nucleosome structure and function in space and time (Nucleosome4D). Our main objective is to provide our young researchers with world-class research & training in nucleosome biology. We will use cutting-edge, interdisciplinary methods and collaborative projects to determine how nucleosomes are remodeled during transcription, when genes are silenced, as cell divide, as stem cells differentiate, during organismal development and in human disease. We utilize state-of-the-art approaches in structural biology, biophysics, cell biology, live-cell imaging, biochemistry, genetics, genomics and bioinformatics. We will implement a comprehensive training plan for scientific and career development using the best local approaches to research & training, by promoting exchanges, using the advise of our industrial partners and three Visiting Scientists, by sharing reagents and expertise, as well as through a structured set of scientific workshops and complementary skills training courses. Together, our effort will ensure the multidisciplinary and intersectorial training of a new cohort of young European researchers. This will allow our trainees to take the opportunities and meet the challenges of a successful career in the life science sector through excellent training, effective communication, great teamwork and proven project management skills.