^aThe parent genes of chimpanzee PPGs are not found in the Ensembl annotation.

^bIncluding five chimpanzee-specific exon loss events.

^cSeven chimpanzee-specific exon loss events are inferred based on the macaque/mouse genomes. The other 46 exons are not found (or identified) in the macaque/mouse genomes.

^dThe 26 exons include four very short exons (<12 bp) and 22 exons of which orthologous chimpanzee genes are not found in the Ensemble annotation.