Comprehensive analysis of IPA events detected by IPAseek. (A) Same as Figure 1A but a composite IPA event detected only by IPAseek. The highlighted region shows the new terminal exon (TE), in which the termination site was detected as a changepoint by IPAseek. The gene locus presented here is located on the sense strand of DNA. (B) Similar visualization as in A but depicting a skipped IPA event detected by IPAseek. The top track here indicates the position of the two nested primers used for 3′-RACE validation. The blue highlighted region shows the TE detected by IPAseek, and the pink highlighted region shows the cleavage site detected by 3′-RACE (±20 nt). The gene locus presented here is located on the sense strand of DNA. (C) Validation of 3′-end detected by IPAseek in B using 3′-RACE. Total RNA extracted from K562 cells was used to perform 3′-RACE.