HIF-1α expression is variable and correlates with HIF-1α target genes in CLL patients. (A) Box plot representing mRNA expression levels of HIF-1α in primary CLL B cells (n = 50). Expression was calculated using the 2^−ΔCt method relative to 18S expression and expressed as log₁₀. The median value was 0.49. (B) Western blot analysis of HIF-1α in primary CLL B cells expressing HIF-1α mRNA levels greater than or less than the median value of 0.49 calculated in panel A and exposed to 1% oxygen for 8 hours to stabilize HIF-1α. Spearman correlation analysis of HIF-1α mRNA levels and mRNA levels of CXCR4 (n = 41) (C) and SLC2A1 (n = 48) (D) in CLL B cells from patients, calculated by the 2^−ΔCt method relative to 18S expression and expressed as log₁₀.