Indeed, loss of GCH1, 6-pyruvoyl-tetrahydropterin synthase or sepiapterin reductase sensitize cancer cells to GPX4 inhibition [53] and overexpression of GCH1 is sufficient to increase resistance to Gpx4 loss and inhibition and imidazole ketone erastin (IKE) treatment [54]. The gene discussed is GPX4; the disease is cancer.