Fig. 2

Altered fragmentation profiles of methylated cfDNA in patients with breast cancer. A–F Distribution of cfDNA fragment size in Input library (blue line) and IP library (red line) were shown for healthy individuals (H1, H2, and H3) (A–C), and patients with breast cancer (P1, P2, and P3) (D–F). The vertical dashed line indicated cfDNA fragment size at 100 bp and 150 bp. G, H Evaluation of short cfDNA fragments ratio changes (defined as the ratio of short cfDNA fragments (100–150 bp) to long cfDNA fragments (151–220 bp)) in IP libraries when compared with corresponding Input libraries were shown for healthy individuals (p = 0.0047, 0.1202 ± 0.0109 vs. 0.1695 ± 0.0103) (G) and patients with breast cancer (p = 0.6217, 0.1446 ± 0.0115 vs. 0.1518 ± 0.0204) (H) in discovery cohort 1. I Genome-wide cfDNA fragmentation profiles (the ratio of short cfDNA fragments (100–150 bp) to long cfDNA fragments (151–220 bp)) in Input (upper panel) and IP (middle panel) libraries were shown in 5-Mb windows for patients with breast cancer (red, N = 3) and healthy individuals (blue, N = 3), changes of cfDNA fragmentation profile (IP-Input, lower panel) were calculated through subtracting the short fragments ratio in Input libraries format in IP libraries and shown in each 5-Mb window. Healthy, healthy individuals; Breast, patients with breast cancer