HOTAIR and breast cancer: For example, a lncRNA HOTAIR (homeobox, HOX antisense intergenic RNA) was overexpressed in ER+ BC cells (MCF7) resistant to the estrogen antagonist drug tamoxifen, in which it promoted the proliferation, while HOTAIR depletion by shRNA lentiviral transduction considerably reduced cell survival and decreased growth during anti-hormone therapy with tamoxifen [99].