Web of Science Group prepares a list that details the scientists shown to have had significant influence through the publication of multiple articles, frequently cited by their fellow researchers. In order to recognise the work of the most influential scientists in their respective disciplines, bibliography experts from the Institute for Scientific Information, Web of Science Group, identify the professionals accumulating more than 1% of the citations in their field and year of publication. This selection method, based on the percentile, eliminates the advantage of citations from older articles compared to those more recently published.

Among the 108 Spanish scientists recognised on the 2021 list, two from Vall d’Hebron Research Institute stand out: Dr Xavier Montalban, Head of the Vall d’Hebron University Hospital Clinical Neurology-Neuroimmunology Department, Head of the Vall d’Hebron Research Institute (VHIR) Clinical Neuroimmunology Research Group and Director of the Multiple Sclerosis Centre of Catalonia (Cemcat), and Dr Maria Buti, Head of the Vall d'Hebron Hospital Internal Medicine and Hepatology clinic, lead researcher of the Vall d'Hebron Research Institute Liver Diseases and assistant researcher at the Biomedical Research Centre Network for Liver and Digestive Diseases (CIBERehd).

The following people from the Vall d’Hebron Campus also appear: Josep Tabernero, Head of the Vall d'Hebron University Hospital Medical Oncology Department and Director of the Vall d’Hebron Institute of Oncology; and Dr Enriqueta Felip, Head of the Vall d’Hebron University Hospital Medical Oncology Department and supervisor of the Thoracic Tumours Unit and lead researcher of the Vall d'Hebron Institute of Oncology Thoracic Tumours and Head and Cancer Group, and Dr Javier Cortés, translational researcher at the Vall d'Hebron Institute of Oncology, Director of the International Breast Cancer Centre (IBCC) and translational researcher at the Vall d'Hebron Institute of Oncology – specialising in breast cancer.

This ranking serves as a reference for the lists of the most cited researchers. It includes around 30 Noble Prize winners and identifies potential future winners of this prestigious award.