1. 1Department of Neurosurgery and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, California;
2. 2Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, New York;
3. 3Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine; and
4. 4Stanford University School of Medicine, Stanford, California