This course provides background information needed to function in mammary tumor biology. It includes case examples and interactive conferences and is designed for the trained scientist (Ph.D., M.D., D.V.M.) with exposure to but limited training in comparative pathology and the use of genetically engineered mice to model human mammary disease. Participants learn to recognize and interpret the significance of the clinical, gross and microscopic findings in mice and to compare and contrast diseases found in mice to those found in other animals, including humans.