Comparison of MRD assessment by consensus PCR with flow cytometry and quantitative PCR. MRD assessment by these techniques in samples from 3 representative patients (cases 1, 2, 3); ▪, MRD⁺ samples by consensus PCR; □, MRD^– samples. MRD levels (y-axis) quantified by flow cytometry and quantitative PCR are shown in logarithmic scale. The majority of samples with MRD levels higher than 10^–2 were positive by consensus PCR, whereas those with levels lower than 10^–3 resulted in MRD^– by consensus PCR. There was a zone represented by a light gray box, in which samples were either positive or negative independently of the MRD level.