As the most well-known and exploited technique in the detection of MRD in MCL, qPCR uses either IgH rearrangements or the Bcl1-IgH rearrangement as its clonal markers and has a high sensitivity and ability to detect 80–95% of MCL (Fig. 2) [1, 19]. The gene discussed is CCND1; the disease is mantle cell lymphoma.