Additionally, there are some other intracellular and adhesion proteins which can help to distinguish these states; e.g., OCT4, increased RORγ transcription factors, ALDH1 enzyme, c-Met, EpCAM, CD44, CD133, CD24, ABCG2, ABC transporter expression, and the marker of cycling cells (Ki67) are characteristic for cancer stem cells. The gene discussed is ABCG2; the disease is cancer.