CD44 and neoplasm: In the ALDH1hi cells group, the tumor is dominated by epithelial tumor cells CD44+CD24low, CD326+CD44+CD24−, and CD326−CD49f+, while in the ALDH1low cells group, CSCs of mesenchymal origin and epithelial tumor cells (CD227+CD44+CD24− and CD44+CD24−CD49f+) are predominant.