Follow-Up. The CTS cohort is followed annually for cancer diagnosis, death, and change of address. Annual linkage between the California Cancer Registry (CCR) and the cohort membership is used to identify incident cancer cases. The CCR is a population-based cancer registry that is anchored in legislation that mandates reporting. It covers the entire state of California, has interstate agreements with 13 other states for case-sharing purposes, is estimated to be over 97% complete, and is part of the National Cancer Institute’s Surveil-lance, Epidemiology, and End Results (SEER) program. Thus, the CCR maintains the highest quality standards so that all cohort members residing in California effectively remain in active follow-up for cancer outcomes. Linkage between the CTS cohort and the CCR database is based