WNT5A and plasma cell myeloma: Although Wnt5a has been reported to promote osteoblastogenesis of human MSCs through Fzd receptors and Ror2 [62], it has been found that myeloma cells in co-culture with pre-OBs inhibit Ror2 expression in the latter, thus impairing osteogenic differentiation and contributing to OB suppression [63].