As PTEN has been shown to increase antioxidant activity, it seems counterintuitive that PTEN could promote senescence or apoptosis, especially when one considers that complete acute loss promoted a strong senescence response that opposes tumor progression [68], even though complete loss of PTEN has been found in many cancers, leading to speculation that loss of PTEN leads to tumorogenesis. The gene discussed is PTEN; the disease is cancer.