GAPDH and B-cell chronic lymphocytic leukemia: CLL cell lines methylated for BM742401 were significantly associated with lower expression of BM742401, as evidenced by RT-qPCR showing a higher ΔCt (Ct BM742401– Ct GAPDH), than those CLL cell lines completely unmethylated for BM742401 (P = 0.032) (Figure 2A).