He is and has been chairman or member of numerous national and international scientific and strategy committees advising in the field of oncology and pathology. He received several awards for his scientific work. Presently he works at the Dept. of Pathology, VUMC, Amsterdam heading a research group aiming to elucidate molecular aspects of HPV infections leading into transforming cervical intra-epithelial neoplasms and cancer and focuses on the role of promotor methylation of tumor suppressor genes involved in carcinogenesis.