PSMB9 and brain ischemia: It is generally believed that LMP2 is a critical component for proteasome activity in that LMP2 is essential for the proper assembly of the immunoproteasome.19 However, recent studies have shown that there are different subtypes/intermediate type proteasomes in several tissue and organs where the LMP7 subunit can be incorporated along with standard catalytic subunits.20, 21 Thus, it is necessary to test the role of LMP2 as a regulator for i-proteasomes assembly in cerebral ischemia.