The research career of Dr. Leonidas Stefanis has evolved from the study of neuronal cell death pathways to the study of the pathogenesis of neurodegenerative disorders. For over 20 years and since his tenure at Columbia University in New York, Dr. Stefanis has studied the role of protein degradation (breakdown) pathways in neurodegeneration, and in particular, their relationship to alpha-synuclein (sticky protein associated with Parkinson's) dysfunction. In recent years, given his dual clinical and research appointment at the University of Athens Medical School and at the Biomedical Research Foundation of the Academy of Athens, he has also been involved in biomarker (marker of disease activity) and genetic studies in Parkinson's and related disorders. On the clinical side, he is interested in neurodegenerative diseases and disorders of cognition, behavior, and movement, of which Parkinson's is a prime example.