As noted by Larrosa et al. (55), both Uro-A and Uro-B showed improved antiestrogenic activity (quantified by their potentials to inhibit the proliferation of MCF-7 in the presence of 1 pM 17β-estradiol) in MCF-7 breast cancer cell line than most phytoestrogens with 0.4 and 0.75 μM IC50 values for urolithin A binding assays with ERα and ERβ and 20 and 11 μM IC50 values for Uro-B binding assays with ERα and ERβ, respectively. This evidence concerns the gene ESR1 and breast cancer.