title: Introduction.
authors.affiliation: The James Homer Wright Pathology Laboratories, Massachusetts General Hospital, Boston, Massachusetts; Department of Pathology, Harvard Medical School, Boston, Massachusetts; Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Young
authors.affiliation: The James Homer Wright Pathology Laboratories, Massachusetts General Hospital, Boston, Massachusetts; Department of Pathology, Harvard Medical School, Boston, Massachusetts; Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Scully
authors.affiliation: The James Homer Wright Pathology Laboratories, Massachusetts General Hospital, Boston, Massachusetts; Department of Pathology, Harvard Medical School, Boston, Massachusetts; Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Ulbright