Project Summary/Abstract The vascular contribution to cognitive impairment and dementia (VCID) due to cerebral small vessel disease (SVD) continues to be recognized as a major public health threat. In response to the call from NINDS for the next phase of a multi-site consortium dedicated to validating biomarkers for SVD-related VCID, we propose the Massachusetts General Hospital (MGH) MarkVCID2 Biomarkers Coordinating Center (CC) to continue as the main driver for consortium activities. The overarching goal for the MarkVCID2 consortium will be to validate biomarkers as being sufficiently informative for direct incorporation into SVD clinical trials, termed as clinical validation. To achieve this goal, the MGH CC will seek 1) to lead the creation of a practical framework for clinical validation to establish candidate biomarker readiness for direct incorporation into clinical trials, 2) to drive each step in the implementation of this framework via active Administrative and Data/Biostatistical Cores and leadership of the MarkVCID2 committee structure, 3) to promote participant recruitment and retention programs that provide full study enrollment including among diverse populations, and 4) to handle all aspects of data curation, management, security, and quality. Specific strengths of the Coordinating Center include its track record as Coordinating Center in successfully establishing and implementing rigorous instrumental and biological validation standards; its clearly defined vision for operationalizing biomarker clinical validation for the major clinical trial contexts of use of subject selection and study outcome; the Principal Investigator's demonstrated high-level skill as a scientific pioneer in SVD biomarkers and an effective leader of complex multicenter projects and organizations; and its experienced team of Administrative and Data/Biostatistical Core directors, co-investigators, and project staff capable of leading all aspects of multicenter study operations and decision-making, multimodal data handling, and biostatistical and analytical design and execution. If selected, the MGH CC will continue to drive all aspects of MarkVCID2 with the goal of building the strongest foundation for effective clinical trials of SVD-VCID disease-modifying interventions.