IL1B and breast cancer: In ad hoc analysis, when labeling the missing values for MHT and parity as such and studying the association between inflammation markers and breast cancer risk for 1300 women, we observed that the associations in the highest category of IL-1β in models III and IV were no longer significant; 1.43 (0.94–2.19), 1.53 (0.98–2.37) respectively.