Contrary to SFRP2, which facilitates infiltration and the metastasis of osteosarcomas [258], SFRP3 is downregulated in osteosarcoma patients at the local and systemic levels [456] and upregulated in bone marrow multiple myeloma samples with advanced lytic bone disease (LBD) as compared to no/limited LBD [457]. The gene discussed is SFRP2; the disease is osteosarcoma.