The LongITools European research project studied the interactions between environmental, lifestyle and biological factors to determine the risks of chronic cardiovascular and metabolic diseases data variables on over 11 million European and UK citizens, from 24 different studies. The data variables are wide ranging and include, for example, height, weight, blood composition, employment, lifestyle factors, cholesterol and many more. Where possible, researchers harmonised the variables in their data sets to an agreed LongITools definition (harmonised model or common data model). MOLGENIS lead the data infrastructure work package, with focus on the data and harmonisation catalogue.