POLR2A and ovarian cancer: Mechanistically, circMETTL6 recruited the non‐POU domain containing octamer binding protein (NONO) by binding to its Coiled‐coil domain and disrupted its binding with RNA polymerase II subunit A (POLR2A), and consequently inhibiting growth differentiation factor 15 (GDF15) transcription, thereby suppressing ovarian cancer progression.