Normal buccal mucosa and tongue from 5 pairs of Tgfbr1f/f/Ptenf/f and Tgfbr1/Pten 2cKO mice, together with tumors that developed in Tgfbr1/Pten 2cKO mice, were carefully dissected. A total of 40 μg of protein from each sample were denatured and then loaded in each lane of NuPAGE 4-12% Bis-Tris precast gel. Additional details are provided in the Supplementary Data.