Detailed levels of FCM MRD and ctDNA for all 4 patients with CLL–type clinical disease progression. FCM MRD is shown in blue, ctDNA of patient-specific VDJ rearrangements in red, and in patients with available CLL-related mutations at baseline (P002, P0014, and P015), the ctDNA level of the somatic mutation is shown in green. In P002 and P006, ctDNA is detected several months before FCM MRD becomes positive and before clinical progression. In P014 and P015, ctDNA and FCM MRD both recur at the same time point. The characteristics of clinical progression are shown in blue boxes. FU1, follow-up staging 1; FU2, follow-up staging 2; FU3, follow-up staging 3; M2, maintenance staging 2; PD, clinical disease progression.