Furthermore, we showed for the first time that overexpressing DANCR in normal MCF10A or low‐malignant MCF7 cells significantly up‐regulated the expression of multiple CSC biomarkers, leading to increased mammosphere formation in vitro and stimulated tumor formation in mice, suggesting that DANCR not only was essential to maintain cancer stemness in late‐stage breast cancer cells but also was sufficient to transform normal breast epithelial cells into tumor‐forming cancer cells and to boost further the stemness of low‐malignant cancer cells. This evidence concerns the gene DANCR and breast cancer.