Summary clonal relationship of paired diagnosis and recurrence cHL samples. (A) Clonal comparison revealed the clonal relationship of paired diagnosis and recurrence samples by NGS-based detection of immunoglobulin rearrangements (IG-NGS). Time interval between the diagnoses and the cHL subtype of each biopsy is indicated. The open diamonds represent recurrences for which no tissue biopsy was available; therefore, molecular analysis could not be performed. (B) The top pie chart shows the proportion of cases with interpretable and nonevaluable data sets within the total cohort, the middle pie chart the proportion of cases with conclusive and inconclusive data sets, and the bottom pie chart the clonal relationship of all cases with conclusive results. Clonally unrelated cHL is subdivided in cases with distinct R or discordant R.