To that end, the Dkk1-4-secreting sublines of the mouse plasmacytoma MOPC315 developed here may provide a starting point, as the tumor cells can be readily transplanted into BALB/c mice where they infiltrate the bone marrow (results not shown) and, possibly, cause osteolytic lesions in dependence on Dickkopf expression. Here, DKK1 is linked to plasmacytoma.