The Carotene and Retinol Efficacy Trial (CARET) was a randomized, double-blind, placebo-controlled trial of the cancer prevention efficacy and safety of a daily combination of 30 mg of β-carotene and 25,000 IU of retinyl palmitate in 18,314 persons at high risk for lung cancer. The trial began recruitment in 1985 and was halted in January 1996, 21 months ahead of schedule, with the twin conclusions of no benefit and substantial evidence of a harmful effect of the intervention on both lung cancer incidence and total mortality. Participants continued to be followed for over nine years post-intervention, with updated lung cancer incidence and cardiovascular disease mortality findings published in 2004. On June 30, 2005, CARET stopped active followup of participants. During the active intervention phase of CARET, serum, plasma, whole blood (for DNA), and lung tissue specimens were collected. These biospecimens make up the CARET biorepository, which is the focus of this application. The CARET biorepository is a key tool in studying disease development and progression. It is an invaluable legacy of the parent trial with specimens available to any investigator with a hypothesis-driven project. The specific aims of the current grant cycle (2013-2018) included extending the database and online accessibility to include participant use of micronutrient, mineral, and vitamin supplements; baseline laboratory values; and stage at diagnosis of lung, prostate, colon, and breast cancer cases. We also extended CARET follow-up of cancer diagnoses, deaths, and causes of death through 2012/13 via linkages to the National Death Index, Cancer Registry of Connecticut, and the Cancer Registries of California and Washington. This has greatly increased the total numbers of identified incident cancer cases (n=6,773) as well as extending the follow-up of the entire cohort (median follow-up to first diagnosis is 18 years and to death is 20 years). In our goal to make the CARET biorepository accessible, during the current grant cycle (2013 – 2018), biospecimens and /or data have been provided to investigators, which have resulted in 23 peer-reviewed publications. Currently there are 93 ongoing projects utilizing CARET biospecimens. In this application, we request funds to continue support of the CARET biorepository and the associated extensive database. We also propose to pilot procedures to obtain updated signed releases of medical records and consent for the utilization of biologic material in the CARET biorepositories consistent with recent developments on obtaining consent for broad research purposes and data sharing. In addition, to position CARET for studies examining the association of tumor heterogeneity and molecular subtypes with etiologic factors and survival, we propose to conduct a pilot to obtain diagnostic lung cancer biopsy/surgical specimens from Washington State CARET participants diagnosed after 2003. This will include obtaining updated release of medical records and consent for broad research purposes and data sharing.