HERV-K env promotes glioma cell survival, ERK/AKT activation, and immune evasion (22).Recent studies further show that HERV-K env increases chemosensitivity in ovarian cancer by inhibiting the NF-κB/P-glycoprotein axis (23), and contributes to glioblastoma stem cell plasticity via OCT4 regulation (24). Here, POU5F1 is linked to ovarian cancer.