XplOit, funded within the i:DSem initiative of BMBF, aimed to develop a software plattform to support data integration, model development and model validation with medical data using semantic tools. As an application scenario XplOit collected and annotated data from patients who had undergone hematopoietic stem cell transplantation at the University Hospitals Homburg and Essen. Our part of the project was to use this data to develop models predicting critical events after transplantation, for example CMV infection / reactivation, graft-versus-host disease or overall survival. Ideally, these predictive models have the potential to warn physicians early and improve clinical care.