We discovered that the sphere-formation ability of ESCA cells was attenuated and the protein levels of cancer stem cell markers (CD133, Nanog, Oct 4, Sox 2, and ALDH1) in ESCA cells were decreased after KCNMB2-AS1 downregulation, suggesting that KCNMB2-AS1 downregulation diminished ESCA cell stemness. The gene discussed is NANOG; the disease is cancer.