Flow cytometry and sphere formation assays indicated that FEZF1-AS1 can reduce the CD44+/CD24- rate and mammosphere-forming ability in Breast cancer stem-like cells (BCSC), and a series of functional experiments indicated that, compared with the control group, knockdown of FEZF1-AS1 can reduce expression of stem factors (Nanog, Oct4, Sox2) and inhibit proliferation, migration, invasion, and growth in vivo of BCSC. The gene discussed is NANOG; the disease is breast cancer.