The NSABP (National Surgical Adjuvant Breast and Bowel Project) Tissue Bank is the central repository of tissue samples (stained and unstained slides, tissue blocks, and frozen tissue specimens) collected from clinical trials conducted by the NSABP. The NSABP Tissue Bank is located at the NSABP Division of Pathology laboratory. The main scientific aim of the NSABP Division of Pathology is to develop clinical context-specific prognostic markers and predictive markers that predict response to or benefit from specific therapeutic modality. To achieve this aim, the laboratory collects the tumor and adjacent normal tissues from cancer patients enrolled into the NSABP trials through its membership institutions, and maintain these valuable materials with clinical follow-up information and distribute them to qualified approved investigators. Currently, specimens from more than 90,000 cases of breast and colon cancer are stored and maintained at the bank.