3.4 Detection of microorganism contamination
In one sample (iw052), only 90.5% reads could be aligned to the human reference genome, which was much lower than other samples (>98%) (Figure S1a ). A review of unaligned reads revealed that 99.3% of them were enterobacterial in origin (Figure S1b ), suggesting sample contamination or infection. We recollected the blood two months later and no enterobacteria were detected in the sequencing data.