PSMB10 and leukemia: Along the same lines, we found that components of the immunoproteasome (Psmb8, Psmb9, Psmb10) are present at lower levels in FLEF compared to BMEF (Fig. 5G), suggesting that their differential extracellular presence [55–57] affect leukemia burden [58, 59] and may render them sensitive to blockage of proteasome-mediated protein degradation [60].