Immunohistochemistry revealed that in the tumor nodule the MIB1-positive, proliferating, centrally located BLM cells depicting a compact, epithelial-like morphology (Fig. 7c) had only a weak cytoplasmic expression of β-catenin (Fig. 7f, parallel slide of Fig. 7c), while the cells in the outskirt of the tumor nodule with a spindle-like, invasive morphology showed a more prominent cytoplasmic β-catenin expression (Fig. 7g, compare to Fig. 1). This evidence concerns the gene MIB1 and neoplasm.