PROM1 and malignant colon neoplasm: The transmembrane glycoprotein CD44 has been used as a marker to isolate CSCs from multiple solid tumors, such as breast [3], head and neck [29], pancreas [30] and also colon cancer [31].Colon cancer cells sorted for CD44+ displayed high tumorigenicity, especially in combination with CD133-positivity, whereas CD44− cells could not form new tumors in immunodeficient mice [19,20].