The subject contract was established to provide a broad range of routine and specialized pathology services in support of studies conducted under contract by the National Toxicology Program (NTP) and for supplemental studies on pathology specimens generated through these studies. The contract also provides critical pathology (including molecular pathology) support for studies conducted by in-house investigators at NIEHS and other NIEHS contract studies. Specifically, the following services are supported by this contract: 1) necropsy and in-house necropsy assistance;2) histology (tissue trimming and processing, slide preparation, and staining);3) histopathological evaluation/interpretation;4) application of specialized qualitative and quantitative morphological procedures (immunohistochemistry, morphometrics, cell proliferation, apoptosis);5) adaptation, development, refinement, application of new techniques in cellular and molecular biology including (but not limited to) genotyping, DNA sequencing, in situ hybridization, DNA and RNA isolation and amplification, and real time, quantitative, and in situ PCR, as well as training in the application of these techniques;6) Pathology Peer Review (including Pathology Working Groups) and Quality Assessment of pathology evaluations and technical support for these activities;7) pathology data entry;8) presentation or publication of pathology data or techniques, or support for these activities;and 9) on-site pathology support. The following work was completed on this contract in the past year: Twelve pathology working group reviews have been completed for the National Toxicology Program;preparation of histologic slides for 90 in-house and NTP projects some of which also included animal necropsies;specialized pathology evaluations for 16 in-house projects;on-site technical support in the NIEHS Histology and Immnohistochemistry Laboratories;on-site pathology support (2 on-site anatomic pathologists);and 2 projects related to preparation of pathology data for presentation or publication. In addition, there are many other projects for the NTP and NIEHS that are in progress, some of which are long term projects involving housing of animals for long periods.