IL13 and breast carcinoma: A significant heterogeneity by the time of follow-up was found for IL-13 (Phomogeneity<0.01; Additional file 1: Table S4) suggesting an increased breast cancer risk for cases diagnosed between two and five years after blood collection [Fully-adjusted models: OR1SD =2.08 (1.18–3.67)], a decreased breast cancer risk for cases diagnosed between five and ten years after blood collection [Fully-adjusted models: OR1SD =0.70 (0.53–0.93)] and no significant association after ten years [Fully-adjusted models: OR1SD =0.93 (0.68–1.29)].