Differential usage of the APs. Examples of the APs in genes that belong to the GO categories of “ribosome” (A), “serine/threonine kinase” (B), “cell adhesion” (C), and “transcription factor” (D). Each number above the horizontal line shows the genomic coordinate. The red and blue arrows represent AP1 and AP2, respectively. For the RefSeq genes, coding and noncoding regions are represented by yellow and blue boxes, respectively.