PT+/p53-KO and PT-/p53-KO mice after 4-NQO treatment were randomized to receive either regorafenib or the vehicle via intragastrical administration for 28 days, all animals were then sacrificed, and their tongue and esophagus were examined for atypical hyperplasia lesions or squamous cell carcinoma. The gene discussed is F2; the disease is squamous cell carcinoma.