The presence of Wnt signalling inhibitors such as Dkk-1 (Glinka et al, 1998; Krupnik et al, 1999; Nusse, 2001; Mao et al, 2002; Kawano and Kypta, 2003; Li et al, 2006; Morvan et al, 2006) can disrupt the repair of bone and its secretion by tumours into the bone can lead to irreparable damage to the tissue. Here, DKK1 is linked to neoplasm.