In other tissues, similar redox–SMAD interactions are at play: in ovarian cancer, GPx3 helps maintain levels of GDF15 (a TGF-β family member) and supports tumor growth, whereas knocking down GPx3 in ID8 cells lowers GDF15, delays ascites onset, and markedly reduces omental tumors in mice [99]. The gene discussed is GDF15; the disease is ovarian carcinoma.