ERG and neoplasm: For 6 of 18 men (33%) with high tumor content cfDNA samples and tissue-based profiles, clear 21q22.2 copy-number deletions (consistent with TMPRSS2:ERG gene fusion) detected by cfDNA WGS was also detected in tissue-based DNA profiling, with TMPRSS2:ERG fusion isoform expression confirmed by tissue-based RNAseq in 5 of 6 men (Supplementary Figure 10, Supplementary Table 1).