Figure 1. Coexpression of β-catenin and hTERT in tumor cells at the invasive front of colorectal tumors. (A) Tumor cells at the invasive front express nuclear β-catenin (inset, black arrows) and display a mesenchymal differentiation. (B) Corresponding tumor cells also express hTERT (inset, white arrows). (C) Tumor cells in central areas of the tumor display weak or no expression of nuclear β-catenin (inset). These cells are characterized by epithelial differentiation. (D) Corresponding tumor cells display weak or no hTERT expression (inset). At 200x magnification.