Transposable elements harbor progenitor sequences for ESR1, TP53, POU5F1-SOX2, and CTCF binding motifs. (A) The same regions of the repeats harbor sequence binding motifs and are observed to be bound by the transcription factor. Filled areas represent the number of instances, at a given position relative to the consensus sequence, observed to be bound by ESR1, TP53, POU5F1-SOX2, and CTCF, respectively. Similarly, the green, purple, red, and orange curves show the number of instances of the ESR1, TP53, POU5F1-SOX2, and CTCF motifs at a given position across all instances of that repeat in the genome. (B) Multiple sequence alignment of the 17 bound instances of the RLTR11B repeat. Columns with >90% identity are in blue and highlight two regions of high sequence similarity. The first region is where the POU5F1-SOX2 motif (Loh et al. 2006) is detectable. Genomic positions of the repeat instances are shown on the right.