PTEN and head and neck squamous cell carcinoma: We thank Dr. Ashok B.Kulkarni of Function Genomic Section, LCDB, NIDCR/NIH for kindly gift of Pten cKO mice HNSCC, Tgfbr1 cKO mice HNSCC tissue and Tgfbr1/Pten 2cKO mice.