One of the central components to the design of the Chemical Effects in Biological Systems database (CEBS: http://cebs.niehs.nih.gov) is the ability to capture not only a comprehensive set of toxicity endpoints, but also study related protocols that enhance a user’s ability to evaluate study outcomes. CEBS serves roles as a cu-rated public repository for all toxicology data arising from the National Toxicology Program’s (NTP) testing program, and as a portal for users to query this data by test article, CAS number, NTP study type and assay endpoint. Data captured in CEBS extends beyond standard toxicological testing e.g. PCR and microar-ray, which when combined with the additional study protocol information makes CEBS a valuable resource for toxicity assessments. The ability to search data in CEBS has recently been extended to include additional query options for reviewing histopathology data. Currently, CEBS has histopathology findings for 512 test ar-ticles. Using workflows (guided search modules), users can access a summary table for site specific neoplasia or customize their search criteria to review specific subsets of histopathology data. Queries of the dataset can provide information on the test articles associated with different NTP defined levels of evidence of carcinogenic activity, tumor morphologies and sites (Sites and Association workflow). The user also has the ability to query the data for statistically significant tumor findings or individual animal neoplastic and non neoplastic findings (NTP Pathology Data workflow). Data can be filtered on the basis of study date, morphology, organ, severity grade, species, sex, route and treatment group type. All data in CEBS in-cluding workflow results can be downloaded.