title: Expression of Concern: Dual regeneration of muscle and nerve by intravenous administration of human amniotic fluid-derived mesenchymal stem cells regulated by stromal cell-derived factor-1α in a sciatic nerve injury model.
authors.affiliation: Journal of Neurosurgery Publishing Group, Charlottesville, VA.
authors.forename: James T
authors.initials: JT
authors.lastname: Rutka