ESR1 and neoplasm: Six tumor types (including BLCA, BRCA, CHOL, LUSC, PCPG, and UCEC) showed significant lower DNA methylation of ESR1 in tumor tissues than healthy tissues and four tumor types (including CESC, COAD, KIRC, and PAAD) significant higher DNA methylation of ESR1 in tumor tissues (Figure 1A).