The availability of an extensive set of vertebrate genome sequences, together with large-scale transcriptome studies, has allowed the discovery of numerous non-canonical ORFs (usually quite short) with evidence of transcription, translation and functional involvement. Orthologs for these ORFs can be detected in many vertebrates, and the time of appearance of a functional mini-gene can be ascertained. Some of these have appeared quite recently in evolution and have already very specific expression patterns in humans.