 For the cross-sectional arm, there will be one study visit for all participants, which will last approximately 1 to 2 hours for participants without RA controls and 2 to 3 hours for participants with RA. For all participants, this visit will include a medical history review; questionnaires regarding health, functional ability, family, education, and work history; and blood and urine collection. For participants with RA, this visit will also include examination of the joints for pain and swelling, X-rays of the hands and feet, and a physical examination. 