The National Cancer Institute, Division of Cancer Prevention?s Cancer Biomarkers Research Group has negotiated an Interagency Agreement with the National Institute of Standards and Technology (NIST) to serve as a Biomarkers Standardization Laboratory and assist the NCI Early Detection Research Network (EDRN) to discover and validate potential biomarkers in the most efficient manner possible. This may be accomplished either by working on the measurements of specific biomarkers as identified by the EDRN or by identifying critical areas where improvements in the measurement infrastructure will have a broad impact on the quality of the biomarker measurements and data. NIST shall design, execute, and interpret experiments in order to perform tasks for the development and testing of reference samples, validation of cancer biomarkers, or analytical validation of biomarker assays. The Agency shall also provide Program Management Support of the effort to be performed under this Statement of Work. Upon receipt of written notification from the NCI Contracting Officer Representative (COR), NIST will begin the development and testing of a reference sample, a biomarker validation project or the analytical validation of biomarker assay. NIST shall establish and maintain the infrastructure, perform quality control assays, standardize reagents for pre-validation and validation assays, and for assay development. Upon acceptance of the assay by the EDRN Steering Committee, NIST will proceed to the validation phase. Parallel assays may be set up in the initiating EDRN investigator?s laboratory and at NIST using protocols agreed upon by the initiating laboratory, NIST, and NCI to support analytical validation. The three initial projects that NIST will undertake are 1) Development of reference samples and inter-laboratory testing to improve the confidence in the measurement of microRNAs; 2) Development of reference samples and inter-laboratory testing for the measurement of circulating tumor DNA (ctDNA); and 3) Validation of the mitochondrial markers for prostate cancer.