The Occurrence of Skin Tumors in Untreated Albino Mice from Dealer's Stock2

Abstract
Eight of 25 untreated albino mice obtained from a dealer developed multiple papillomas, sebaceous adenomas, and carcinomas. The F2 generation of these mice, bred in this laboratory, did not develop spontaneous tumors or show any response to repeated applications of croton oil. A previous demonstration that croton oil exhibits carcinogenic action in these mice is discussed.