For laboratory tests, overnight fasting blood samples were provided by the Institutional Tissue Bank at FUSCC (for cases). After the questionnaire interview and physical measurements, 10 ml of overnight fasting blood samples were collected for long-term storage in Taizhou Longitudinal Study (for controls).17 (link) For a subset of 305 cases and 330 matched controls who had genotype data during a similar time period, plasma adiponectin levels were measured with commercial enzyme-linked immunosorbent assay (ELISA) kit (Abcam Adiponectin Human ELISA Kit, USA) according to the manufacturer's manuals. The minimum detectable dose was 0.7 ng ml−1. The intra- and inter-assay coefficients of variation were 4.5% and 8.7%, respectively.