HOXC11 and breast carcinoma: We speculated that NR_047517 (HOTAIR‐N) and its promoter accounted for the induction of HOTAIR in lrECM 3D culture of Claudin‐low breast cancer cells because its transcription start site is located in the first intron of the HOXC11 gene and distant from the promoters for the other two HOTAIR isoforms (Fig. 5B).