ESR1 and cancer: The results in Figure 2 summarize studies showing that ERα interacts with Sp1 to activate several genes in cancer cell lines, and these include TNFα [18], E2F1 [19,20], BRCA1 [21], insulin-like growth factor receptor 1 (IGFR1) [22], LDL receptor [23], multidrug resistance (MDR) gene [24], cyclin D1 [25], bcl2 [26], adenosine deaminase [27] and retinoic acid receptor α (RARα) [28], cfos [29], IGFBP4 [30], thymidylate synthase [31], DNA polymerase α [32], carbamyl phosphate synthetase/aspartate carbonyl-transferase/dihydroorotase (CAD) [33], Hsp27 [34], VEGF [35] and MCL-1 [36].