PSME2 and cancer: There was no significant difference in antigen release from tumor cells (step 1) between the groups that had high and low PSME1 and PSME2 expression, but cancer antigen presentation (step 2), priming and activation (step 3), trafficking of most immune cells to tumors (step 4), infiltration of immune cells into tumors (step 5), T cell recognition of cancer cells (step 6), and killing of cancer cells (step 7) were significantly higher in patients with high expression of PSME1/2 than in patients with low expression of PSME1/2 (Figures 12A,B).