HIF1A and plasma cell myeloma: Our results showed that in MMSA-1+U266 cells, hypoxia-inducible factor HIF-1a and adhesion molecule CXCR4 was significantly up regulated, while E-cadherin was greatly down regulated, compared with the other U266 cells, as shown in Fig. 6A and B. Moreover, we also found that angiogenesis promoting factors such as VEGF-A, Ang-2 were dramatically elevated, while Ang-1 was significantly regulated, as shown in Fig. 6C. All these results proved the pivotal role of MMSA-1 played in the interaction between myeloma cells and bone marrow microenvironment.