HOTAIR and breast cancer: To determine its role in BC development, we explored the expression of lncRNA HOTAIR in BC cells (MDA‐MB‐231, SKBR3, MCF‐7) and normal cells (MCF‐10A), and found that the expression of lncRNA HOTAIR was considerably increased in the BC cell lines compared to MCF‐10A cells (P < 0.05, Fig. 1E).