Core B: Clinical Core Project Summary/Abstract The UCI ADRC Clinical Core enrolls, characterizes and follows a cohort of individuals who are cognitively unimpaired, cognitively impaired, or demented, each of whom complete the Uniform Data Set (UDS) consisting of physical and neurological exams and a battery of neurocognitive assessments. In addition to this UDS, participants and their study partners complete questionnaires and assessments unique to our ADRC, and voluntarily contribute a variety of tissue and biomarker assessments, including genetic analyses, volumetric imaging, cerebrospinal fluid analyses, and donation of fibroblasts for the generation of induced pluripotent stem cells (iPSC). Overall, 292 of our current 330 active participants have donated fibroblasts or peripheral blood mononuclear cells (PBMCs), which have been used to generate 192 iPSC lines by our iPSC Core. Most participants agree to brain donation at autopsy and we have a high rate of successful completion of autopsy confirmation at death. Our UDS cohort currently includes 330 active participants. Among this cohort, 60% are female and one third are non-White race or Hispanic ethnicity. Nineteen percent are demented, 18% meet criteria for Mild Cognitive Impairment (MCI), and a majority (60%) do not meet diagnostic criteria for MCI or dementia. Our overall retention rates are very high and above the median for the ADRC system. Most UDS participants have been enrolled in externally funded ancillary studies, ranging from telephone interview studies to neuroimaging biomarker research. To support the increasing needs of ADRC investigators, including novel studies of molecular and vascular biomarkers, we will grow this UDS cohort to a steady state n=400, with an emphasis on enrolling individuals who enable novel studies in support of the UCI ADRC theme “to identify, quantify, and validate factors that influence the risk of AD across the lifespan.”!