To better examine the requirement of NELF-E during EMT induction and progression, as well as its interplay with EMT transcription factors (TFs), we leveraged the doxycycline (Dox)-inducible SLUG and SOX9 MCF7ras breast cancer cell line (henceforth referred to as MCF7ras+SS)40,41. This evidence concerns the gene SOX9 and breast carcinoma.