Here, we show that two SDHD variants SDHD-G12S and SDHD-H50R as well as SDHD knockdown lead to more oxidized PTEN and increased nuclear PTEN accumulation under peroxide-induced oxidative stress, which consequently induced resistance to apoptosis and increased migration in thyroid cancer cells. The gene discussed is SDHD; the disease is thyroid gland carcinoma.