HMOX1 and B-cell chronic lymphocytic leukemia: Moreover, HMOX1 and MMP9 were also significantly upregulated upon incubation of EHEB cells with 3 or 5 μM ATO (Figure 3C) and of primary CLL cells with 2 or 3 μM ATO (Figure 3D), thus confirming the results obtained on MEC-1 cells.