FXYD5 in C0 FXYD5+ TCs deserved our attention, as it had been shown to activate TGF-β/SMAD signaling and drive EMT to promote ovarian cancer progression, and to form a positive feedback loop to drive EMT during the progression of ovarian cancer and to promote tumor growth and metastasis (89); meanwhile, recent study also showed that FXYD5 was upregulated in various tumor types and positively correlates with tumor progression (90). This evidence concerns the gene FXYD5 and ovarian cancer.