Аннотация:Breast cancer (BC) remains one of the leading causes of cancer deaths among women worldwide. Recently, studies of long non-coding RNAs (lncRNAs) involved in the regulation of various signaling pathways in cells have become increasingly important, since they demonstrate great prognostic potential in cancer. The aim of our work was to identify new aberrantly expressed lncRNAs in BC. We identified 30 aberrantly expressed lncRNAs in BC. For most lncRNAs, a decrease intheexpression level by2.34–13.2times(p<0.05) wasnoted,andonly forlncRNATERC,anincrease in the expression level by 2.24 times (p = 0.034) was noted. Of greatest interest are the data obtained for the lncRNAs ADAMTS9-AS2, EMX2OS, HOTAIRM1 and MEG3, as they are consistent with the data of the bioinformatic analysis.