JAG1 and cancer: This aligns with the well-known tumor suppressor function of PLK2 in various human cancers.26,27 To further investigate whether PLK2 counteracts KDM5B-driven tumor progression, we introduced simultaneous overexpression or knockdown of KDM5B and PLK2 in HONE1-EBV, CNE2-EBV and AGS-EBV cells.