Funding for this research was provided by:
National Cancer Institute (R01 CA77398)
Received: 12 July 2016
Accepted: 20 October 2016
First Online: 1 November 2016
Compliance with ethical standards
: The authors declare they have no conflict of interest.
: All procedures performed in the California Teachers Study involving human participants were in accordance with the ethnical standards of the Institutional Review Boards of the Cancer Prevention Institute of California, City of Hope National Medical Center, the University of Southern California, the University of California at Irvine, and the California Health and Human Services Agency and were in compliance with the 1964 Helsinki Declaration and its later amendments or comparable ethnical standards.
: Informed consent was obtained from all individual participants included in the study.