Schematic representation of a TCF3 locus including translocations and transposable elements. The red triangles represent individual translocation junctions, the blue arrows indicate transposable elements within TCF3, and the black rectangles identify TCF3 exons. Inset, TCF3 translocation junction density map within the MER20 transposon. Genome coordinates correspond to March 2006, NCBI36/hg18 human genome assembly. TCF3: Transcription factor 3; MER20: Medium reiteration frequency repetitive 20; L1: LINE-1 Long INterspersed Element 1; L2: Long INterspersed Element 2; Alu: Alu SINE; U6: Small nuclear RNA.