This is consistent with ER-negative/basal-like breast cancers showing higher immune infiltration compared to ER-positive/luminal tumors [60], as the methylation of cluster 2 CpGs was significantly lower (Additional file 1: Fig. S9c, d) and the miRNAs of cluster A were more expressed (Additional file 3f) in ER-negative/basal-like tumors. Here, ESR1 is linked to breast cancer.