ATP2A2 and B-cell chronic lymphocytic leukemia: Figure 2A showed that CLL cells exhibited a significant up-regulation of KCNN4 (4.52 ± 1.73 vs. 0.58 ± 0.2), MCU (0.76 ± 0.05 vs. 0.56 ± 0.11), IP3R3 (1.74 ± 0.73 vs. 0.62 ± 0.13), and ATP2A2 (2.12 ± 0.29 vs. 1.17 ± 0.23), and a down-regulation of VDAC1 (0.35 ± 1.73 vs. 0.51 ± 0.12). These results suggested that alterations in these regulators of Ca2+ homeostasis represented a hallmark of CLL cells, which might render them sensitive to Ca2+-targeting agents.