HIF1A and B-cell chronic lymphocytic leukemia: After exposure to M2–10B4 SCs, the production of cholesterol and FPP (Figure 3A), the amount of GTP-bound RhoA and the activity of RhoA kinase (Figure 3B), the transcriptional activity of HIF-1α, and the expression of its target gene MDR1 (Figure 3C) were significantly increased in IGHV UM but not in M CLL cells (p always ≤ 0.03).