RUNX2 and neoplasm: Within the tumour-bone microenvironment, it is known that cancer cells can express markers typically associated with bone cells, including osteopontin, osteocalcin, RUNX2 and RANKL (Koeneman et al, 1999; Brubaker et al, 2003; Zayzafoon et al, 2004; Huang et al, 2005; Fradet et al, 2013).