DANCR and breast cancer: Although the knockdown of DANCR by shDANCR was not ideal, by comparing several malignant phenotypes between shDANCR and shNC cells, we found that knocking down DANCR significantly reduced the viability (Fig. 2B,C), induced cell‐cycle arrest at G0/G1 phase (Fig. S1), and inhibited both the migration (Fig. 2D,E) and the invasion (Fig. 2F,G) of both MDA‐MB‐231 and MDA‐MB‐468 cells, suggesting that DANCR essentially maintained multiple malignant behaviors of breast cancer cells.