SMAD4 and neoplasm: In the xenografts TB is reduced, tumor cells are pSTAT3 negative (indicating absence of cytokine/chemokine signaling), some are partially positive for pERK1/2, with maintenance of nuclear β-catenin and SMAD4 immunostainings, and WNT and BMP pathway activation. KRAS/BRAF mutational status did not correlate with TB or podia formation in the xenografts