AID expression can change over time in some B-CLL cases. (A) Schematic representation of the AID RT-PCR results on 17 B-CLL cases at different time points. AID amplification was performed by using the primers 63F and 415R for 33 cycles. The open boxes represent PCRs without a detectable product; the filled boxes are a detectable product. The numbers in the boxes correspond to the number of years counted from the first tested sample date. (B) Real-time quantitative PCR results on B-CLL cases at different time points. The labeling of the graph and PCR conditions are as for Figure 2.