ESR1 and breast cancer: To compare the T-oligo effect to that of a recognized anti-breast cancer chemotherapeutic agent, cisplatin [44-48], and to an anti-estrogen frequently used to treat estrogen receptor positive breast cancers [49-51], MCF-7 cells were treated with customary doses of cisplatin (10 μM), the anti-estrogen ICI 182,780 (100 nM) or T-oligo (40 μM) as above (Figure 6).