TGFB1 and carcinoma of esophagus: (N, O) Immunoblot analyses of whole-cell lysates of MDCK II cells (N) expressing KRAS G12V treated with 5 μg/ml TGFβ for 0, 3, and 8 days and human esophageal carcinoma cell lines TE-15 and TE-8 (O).