The expression of Smad6 and Smad7 were both altered by TGFβ1 stimulation in both mouse StHdhQ111 and human NPC lines (Fig. 2); there was increased expression of Smad6 when homozygous Q111 alleles were present in the absence of TGFβ1, and in StHdhQ7/111 cells in the presence of TGFβ1. This evidence concerns the gene SMAD6 and nasopharyngeal carcinoma.