Query: Where does the Washington University School of Medicine rank in student selectivity?
Context: The Washington University School of Medicine, founded in 1891, is highly regarded as one of the world's leading centers for medical research and training. The School ranks first in the nation in student selectivity. Among its many recent initiatives, The Genome Center at Washington University (directed by Richard K. Wilson) played a leading role in the Human Genome Project, having contributed 25% of the finished sequence.