Changes of the osteoblasts after cultured with bortezomib. (a) After co-cultured with bortezomib, the quantity of osteoblasts from MM patients was more than those without bortezomib (*P < 0.05). (b) The expressions of BMP2 mRNA were detected by RT-PCR. The BMP2 expression of osteoblasts from MM patient (line a,c) was negative. The BMP2 expression of osteoblasts from normal controls (line b) and that of osteoblasts from MM patient co-cutured with Bortezomib (line d), were both positive.