CD44+CD24‐ and ALDH+ are the most common markers of BCSCs.[10, 11] Increased levels or activities of the ALDH enzyme indicate a high tumorigenic potential of cancer cells and the ability of CSC self‐renewal.[12] Emerging evidence suggests targeting CSCs may be effective approach for anti‐cancer treatment.[13] An in‐depth understanding of the mechanisms underlying the CSC stemness property is critical for eradicating CSC. This evidence concerns the gene CD44 and cancer.