Breast cancer cell lines overexpressing AQP5 (AQP5 cells) showed greater sensitivity to hydrogen peroxide, with a significant decrease in viability observed at 20 μM (MCF7-AQP5: p = 0.0205; SkBr-3-AQP5: p < 0.0001; SUM 159-AQP5: p = 0.0022). The gene discussed is AQP5; the disease is breast carcinoma.