XBP1 and cancer: A number of cancer vaccines that target multiple TAAs have been developed for therapy against TNBC, including the PVX-410 vaccine that consists of peptides derived from the transcription factor X-box binding protein 1 (XBP1), the plasma cell marker syndecan-1 (CD138), and the NK cell receptor CD319 (CS1), as well as STEMVAC, a DNA vaccine encoding multiple peptides of CD105 (Endoglin), Y-box binding protein 1 (Yb-1), SRY-box 2 (SOX2), cadherin 3 (CDH3), and murine double minute 2 (MDM2) proteins.