Carcinogenic Effect of Prolonged Exposure to Grenz Ray11From the Departments of Dermatology and Pathology, Baylor University College of Medicine, Houston, Texas.Supported in part by Contract No. DA-49-007-MD-953, Medical Research and Development Command, Department of the Army, Office of The Surgeon General.Presented at the Twenty-second Annual Meeting of the Society for Investigative Dermatology, Inc., New York, N.Y., June 29, 1961.