What are the causes of disease? We know that most diseases result from a combination of genes and environment (nature and nurture). Our genes alone do not determine our fate. For most complex diseases, externalities - environmental factors in the broad sense - are more important. This includes our living and working environments, diet, social support and stress, pollution, and exposure to infectious agents. Exposome research is about discovering the non-genetic drivers of health and disease. Derived from the term exposure, the Exposome represents the totality of exposures we face throughout our lifetime. It also represents the biological responses that arise from external exposures. In this course, 7 researchers from Utrecht University and/or the NWO Gravitation programme Exposome-NL will offer their expertise. We will introduce you to the Exposome concept; why it's important; how we measure the exposome; and the data sciences steps needed to establish associations with health outcomes. This course will conclude with reflections on what is needed to advance this nascent and transformative field of research. Exposome research requires transdisciplinary approaches. Therefore, this MOOC will be of interest to current and prospective students and researchers in the fields of public health, environmental health, life sciences, clinical medicine, geosciences, humanities, and social and behavioural sciences.