Study site: The study will be conducted at the NIH-funded General Clinical Research Center (GCRC). The GCRC provides state of the art resources including research space, specialized research nurses to perform blood draws and gather biodata, biostatisticians, and sophisticated laboratories to perform serum biomarker analysis. OHSU's GCRC is Oregon's premier multidisciplinary patient-oriented research facility and is housed in the same building as the CPC, thus minimizing travel burden on participants.