Fig. 4.

(A) Somatic L1 insertions are biased toward hypomethylated regions in cancer cells. Colon cancer regions were assessed in independent samples. (B) A model of TE insertion preferences and subsequent selection process that bias genomic distribution of TE insertions is illustrated. Somatic insertions are strongly biased toward cancer-specific DNA hypomethylation regions (red box) and encounter selection that depletes them from transcriptionally active genes unless such insertions promote tumorigenesis. By contrast, germline insertions are biased toward germline-specific DNA hypomethylation domains (blue box) and are depleted from all genes.