RUNX2 and fibrous dysplasia: In this paper, a Tissue Microarray (TMA)-based immunohistochemical evaluation of the expression of β-catenin, cadherins (E-cadherin, N-cadherin, P-cadherin, OB-cadherin) and P-Runx2 was performed in formalin fixed, paraffin embedded samples from nine patients affected by fibrous dysplasia (n.8) and HPT-JT syndrome (n.1), and in seven controls, represented by reactive fibromyxoid tissue, reactive mature fibrous tissue, normal bone with hematopoietic cells and remodeling bone surrounding developmental odontogenic cyst.