Fig. 3

Differential methylation levels for cg00452016 (A, B), cg01667837 (C, D), and cg04990372 (E, F) between dichotomized income groups. For each of the CpG sites, linear regression was used to test association between income levels and DNA methylation within estrogen receptor (ER)+ or ER− subgroups, or within Black or White subgroups. Regression models were adjusted for age at diagnosis, and race (when stratified by ER status) or ER status (when stratified by race). The adjusted p values are shown. The average methylation level differences between the two ethnic groups and the two ER status groups were also tested using Mann–Whitney U test and the p values are labeled on top