A further study of 171 patients diagnosed with MM suggested that the extent of osteolytic bone disease was positively related to the overexpression of DKK1, and forced overexpression of DKK1 in plasma cell myeloma has been shown to cause osteopenia, hematopoietic stem cell function deficits, and fracture repair inhibition (Tian et al., 2003; Politou et al., 2006; Kaiser et al., 2008; Zhou et al., 2013). The gene discussed is DKK1; the disease is plasma cell myeloma.