Fragmentation analysis of MCL ctDNA reveals increased fragmentation of molecules. (A) Heat map showing the fragment density distribution of pretreatment cfDNA in patients with ctDNA detected (39 patients, columns). Red indicates a higher number of fragments; blue lower. Select fragment lengths indicated (y-axis). Fragments between 50 and 500 base pairs shown. (B) Line graphs showing fragment length distribution according to mutated and reference fragments of MCL reporters in the pretreatment samples (n = 39 samples, 876 mutations). Additional line graphs showing mutant fragment enrichment (right upper corner), VAF, and correlation of fragment density (right bottom corner) with ctDNA parameters according to fragment length (x-axis). (C) Scatterplot of pretreatment cfDNA samples according to submononucleosomal (x-axis) and subdinucleosomal (y-axis) fragment fractions in the pretreatment samples. Spearman correlation. (D) Dot and box plots of submononucleosomal fragment enrichment in different sample types. Lines connect patients with pretreatment and on-therapy samples available; dots are colored according to clinical response or controls. Mann-Whitney U test P values for comparisons are shown. PD, progressive disease.