Vassilis Pachnis was born and raised in Greece. He graduated from the University of Athens in 1980 where he studied Medicine. From 1980 until 1986 he worked for his PhD in the laboratory of Professor Shirley Tilghman at the University of Pennsylvania/Fox Chase Cancer Center (Philadelphia, USA). From 1986 until 1991 he did postdoctoral work in the laboratories of Dr Richard Axel and Dr Frank Costantini  at Columbia University (New York, USA). In 1991 he moved to the UK and since then has been a research group leader, first at the MRC National Institute for Medical Research and subsequently at The Francis Crick Institute.