By inducing ROS-mediated STAT3 degradation or downregulation, the metal chelator KS10076, a novel dihydroxy-DHA derivative 13R, 20-dihydroxydocosahexaenoic acid (13 R, 20-diHDHA), and flower flavor phenylacetaldehyde (PAA) were reported to be potential agents for targeting CSCs by reducing the size of the tumorsphere and tumor formation, decreasing the expression of CSC self-renewal genes, and decreasing the ratios of subpopulations of ALDH+ or CD44highCD24low (CD44+CD24−) CSCs in colon and breast cancers [131–133] (Fig. 5B). Here, CD44 is linked to breast cancer.