Abstract
Detailed reference data are given for survival and for all types of neo-plastic lesions found in inbred NZO/B1 mice from the original colonies. NZO/B1 mice are unusual in producing malignant lymphomas of Peyer's patches, and a high incidence of duodenal and lung tumours. They are very responsive to most chemical carcinogens. The significance generally of the data is briefly discussed, and reference statistics for neoplasms with more than 1% incidence in untreated animals are tabulated to assist other laboratories studying NZO/B1 mice.