 He is also known for his study, writings, and lectures about the origins of the Jewish people.He is a Professor of Pathology and Genetics at Albert Einstein College of Medicine of Yeshiva University and Director of Genetic and Genomic Testing at Montefiore Medical Center.For the prior 21 years he was Professor of Pediatrics, Pathology and Medicine and Director of the Human Genetics Program at New York University School of Medicine.