ESR1 and breast cancer: We found no evidence of association between blood DNA methylation measured at individual CpG sites and breast cancer risk (Fig. 1, q > 0.59) overall, or after stratification by age (< 50, > 50 years old), ER status (ER+/−), stage (early/late), or time since blood collection (< 5, 5–10, > 10 years) (data not shown).