Effect of Cyclophosphoramide, 6-Mercaptopurine, Actinomycin D and Vincaleukoblastine on the Acquisition of Delayed Hypersensitivity (DNCB Contact Dermatitis) in the Guinea-Pig11From the Department of Dermatology, University of Pennsylvania School of Medicine, Philadelphia 4, Pennsylvania.This study was supported in part by U.S.P.H.S. Training Grant 2 G-62.This investigation was carried out during the tenure of a postdoctoral fellowship, held by Dr. Maibach, from the Division of General Medical Sciences, United States Public Health Service.Cyclophosphoramide (Cytoxan®) was supplied by Paul A. Walter, M.D., Mead Johnson Laboratories, Evansville 21, Indiana; 6-mercaptopurine by Donald S. Searle, M.D., Burroughs Wellcome Co., Tuckahoe, N.Y.; vincaleukoblastine by J. A. Armstrong, M.D., Eli Lilly and Co., Indianapolis 6, Indiana; and Actinomycin D by Elmer Alpert, M.D., Merck Sharp and Dohme, West Point, Pa.Presented at the Twenty-second Annual Meeting of The Society for Investigative Dermatology, Inc., New York, N.Y., June 28, 1961.