ESR1 and neoplasm: To assess if phytoestrogens inhibit tumor growth and/or tumor initiation in a DAXX-dependent manner, ER+ MCF-7-enriched TICs expressing or depleted for DAXX (Fig. 6a) were injected into female, athymic nude, ovariectomized mice to measure rates of tumor growth and tumor initiation when treated with E2 or a phytoestrogen.