Immunohistochemistry (IHC) to investigate mesenchymal characteristics and mineralization capability. Quantification of mesenchymal marker expression. IHC for vimentin (A) and β-catenin (B) was evaluated by counting the number of positive cells up to a total of 500 for each sample in a randomly-selected area containing microcalcifications. β2-M (C), BMP-2 (D) and OPN (E) were evaluated assigning a score from 1 to 3 according to the intensity of positive signals in randomly-selected regions containing microcalcifications. Immunohistochemical data are reported in the table; horizontal bars in the graphs represent significant differences (*P<0.05; **P<0.01; ***P< 0.001).