SMAD7 and hepatocellular carcinoma: However, in a larger patient cohort, our group recently described that SMAD7 in the mean is increased in tumor tissue compared with the surrounding tissue.7 These differences reflect the heterogeneity of HCC and, as discussed in Feng et al.,7 are probably due to different staging of the HCC, the grade of underlying cirrhosis or fibrosis and other patient characteristics subclassifying the cohorts analyzed.