ESR1 and breast neoplasm: Multivariate linear regression analysis controlling for age, race, menopausal status, stage, and multiple comparisons using FDR identified 467 CpG sites in 350 genes that were significantly (P <0.05) differentially methylated according to HR status (ER+ or PR+ or both versus ER-/PR-), 341 CpG sites in 264 genes that were significantly differentially methylated between basal-like and luminal A breast tumor subtypes, and 402 CpG sites in 296 genes that were significantly differentially methylated between p53 mutant and wild-type breast tumors.