He studied biology and molecular genetics at the University of Pavia, Italy.

His PhD work on hemoglobins and haptoglobins has been carried out at the Dept. of Human Genetics of the University of Leiden, and has led to the chararcteriation of the spectrum of mutations leading to haemoglobinopatheis in The Netherlands.

In 1990 he started his post-doctoral work on the molecular genetic basis of colorectal cancer within the same department. As a fellow of the Royal Dutch Academy of Science (KNAW) he visited the laboratory of prof. Raju Kucherlapati at the A. Einstein College of Medicine in New York, where he developed the first targeted mouse model for intestinal tumorigenesis.

In 2001, he has been full professor of Cancer Genetics at the Center for Human & Clinical Genetics of the Leiden University Medical Center (LUMC). His group has contributed to the elucidation of the molecular basis of hereditary colorectal cancer in man, developed a large number of pre-clinical mose models for colorectal carcinogenesis, and characteried novel functional aspects of the APC tumor suppressor gene.

Most recently, the focus of his research has been centered around the role of APC and b -catenin in embryonic and stem cell differentiation.

Since 2003 he is professor of Experimental Pathology at the Josephine Nefkens Institute of the Erasmus Medical Center in Rotterdam.

In 2005, he became member of the European Molecular Biology Organization (EMBO).