Four shape classes of static TSS usage. Tag clusters were classified into four classes based on CAGE tag counts from all tissues. The tag counts are displayed by histograms, where the x-axis indicates genomic coordinates or chromosomal location, and the y-axis indicates the total counts of CAGE tags. bp, base pairs; CAGE, cap analysis of gene expression; TSS, transcription start site.
Kawaji et al. Genome Biology 2006 7:R118 doi:10.1186/gb-2006-7-12-r118