The inhibition profile by IXA vs. BTZ of two constitutive proteasome (cP) subunits β5 and β1 and their immunoproteasome (iP) counterparts β5i and β1i was examined in CEM (ALL) and THP-1 (AML) WT cells and their BTZ7 (low level of BTZ resistance) and BTZ200 (high level of BTZ resistance) sublines (Figure 1). Here, CASC3 is linked to acute myeloid leukemia.