The continuing educational mission of the Registry has been carried out through distribution of 35 study sets, 59 consultations with investigators of animal tumors and poster presentations at scientific meetings. New materials in the form of glass slides and paraffin blocks, have been acquired for entry into Registry files. The most recent has been acquisition of a series of allogenic and spontaneous tumors in nude mice. Analysis of mouse lymphomas has continued with 150 examples studied for morphology, gene rearrangements and immunologic phenotype. A classification of these lymphomas employing the Kiel Classification (in conjunction with Dr. Karl Lennert, Zentrum Pathologie, Kiel, Germany) will be proposed in publications and at meetings. Collaborative work is ongoing in an immunocytochemical study of rat nasal tumors to try to establish primary sites and possible expression of oncogenes. A preliminary study showed lack of expression of p53 in rat esophogeal squamous cell tumors. Acquisition of automated immunostaining capability has initiated planning for a large-scale project utilizing Registry material. The machine will be housed in the Registry for use in in situ hybridization as well as immunologic studies.