While effects of immunoproteasome inactivation on antigen presentation and T-cell activation have been investigated in very detail (reviewed in [12]), our data describes a so far unidentified cell-intrinsic mechanism of immunoproteasome inhibition in the context of KMT2A-r AML: pharmacologic inactivation of its catalytic subunit PSMB8 results in increased abundance of the transcription factor BASP1 and leads to repression of KMT2A-target genes (Fig. 8). Here, BASP1 is linked to acute myeloid leukemia.