For breast cancer, Sha et al. (2017) used MDA‐MB231 cells as the model system and demonstrated that knocking down DANCR was sufficient to reduce the expression of CSC markers, CD44, ALDH, and ABCG2, which correlated with inhibited xenograft formation in vivo. Consistent with Sha et al.’s findings, we showed that knocking down DANCR in TNBC cells potently reduced the endogenous expressions of CD44, CD133, OCT3/4, and Nanog, which was correlated with inhibited mammosphere formation in vitro and xenograft formation in vivo from shDANCR‐targeting TNBC cells. This evidence concerns the gene CD44 and breast cancer.