About the Authors
Institute of Biotechnology, University of Helsinki, Helsinki, Finland
Finnish Institute of Occupational Health, Helsinki, Finland
National Institute for Health and Welfare, Helsinki, Finland
Department of Mathematics, University of Turku, Turku, Finland
The authors have declared that no competing interests exist.
Conceived and designed the experiments: SM TAN. Performed the experiments: NL TÖ JR. Analyzed the data: NL TÖ TA SM TAN. Contributed reagents/materials/analysis tools: IJ TA. Wrote the paper: NL SM TAN.