Copyright information:Taken from "Molecular archeology of L1 insertions in the human genome"Genome Biology 2002;3(10):research0052.1-research0052.18.Published online 19 Sep 2002PMCID:PMC134481.Copyright © 2002 Szak et al., licensee BioMed Central Ltd Lengths of the 16,266 TSDs found by TSDfinder for L1s in the genome are shown as a histogram. The line indicates the average TSD score for each TSD length. The axis displays the range of TSD lengths in nucleotides; the axis displays the number of TSDs. The bimodal distribution suggests that a significant fraction of the 9-11-nucleotide TSDs may be artifactual.