Fig. 3From: Metformin induces ferroptosis through the Nrf2/HO-1 signaling in lung cancerEffects of metformin on the accumulation of cellular ferrous ions. Cells were treated with different concentrations of metformin for 48 h, the intracellular ferrous ions amount were tested by a ferrous iron colorimetric assay. n = 3, *P < 0.05 compared with the control groupBack to article page