ESR1 and breast cancer: As indicated in Figure 5A, upregulated genes such as BMP4, GSTM3, FOS, HMGCS2, ADH1B, COL4A5, ESR1, NAT1, IL6ST, and PGR were enriched in pathways in cancer, chemical carcinogenesis, ECM–receptor interaction, tyrosine metabolism, valine, leucine and isoleucine degradation, the PI3K-Akt signaling pathway, estrogen signaling pathway, caffeine metabolism, signaling pathways that regulate the pluripotency of stem cells, and BC (Table 9).