ERN1 and ovarian carcinoma: FOXK2, a stemness-specific transcription factor highly expressed in ovarian cancer, can bind to the intronic regulatory element of the target gene ERN1 to directly upregulate IRE1α expression; this leads to selective splicing of XBP1, after which spliced XBP1 (sXBP1) acts as a transcription factor to further promote other gene transcriptions.