ABCG2 and neoplasm: Combined effects of silencing SOX2 and Pax treatment on mammospheres indicated that contrary to Pax treatment of unsilenced mammospheres, SOX2-silenced mammospheres from human tumor tissues treated with Pax showed significantly reduced expressions of ABCG2, OCT4, NANOG and ALDH1A1, concomitant with degradation of silenced mammospheres (Fig. 5C, p < 0.01).