SOX21 and cancer: To explore the role of YB-1 in the reversion of differentiated cancer cells into cancer stem cells, the expression of 25 stemness-related transcription factors (OCT-4, RFX4, SOX5, SOX21, MYCL1, SOX2, POU3F2, SOX1, LHX2, VAX2, SALL2, OLIG1, SOX8, ASCL1, HES6, OLIG2, CITED1, HEY2, Klf 15, Bmi-1, SALL4, MYC, ZFP57, POU3F3, and TCF3) in YB-1 wild-type, YB-1 knockout, and YB-1 rescue cancer stem cells was characterized.