PSMB9 and neoplasm: The main changes in the tumor are following: (1) the formation of new proteasome structures with LMP2 subunit in quantity exceeding three times the initial level; (2) the formation of new proteasome structures with LMP7 subunit in approximately equal numbers compared to the initial level; (3) the expression of the additional quantities of 19S and PA28αβ activators; (4) the increase in the total proteasome pool; (5) the enhance of CL, ChTL, LMP2 and LMP7 activities, especially LMP2 activity in the structure, containing PA28αβ activator; (6) the decrease in the content of MHC class I molecules.