Four examples of chimerical retrogenes. A. both of the two terminuses was added a new peptide. B. new peptide was added to its N terminus. C. new peptide was added to its C terminus. D. part of the N terminus was change to 5'UTR. Limegreen box, used retrogenes. Teal box, parental CDS regions. Blue box, chimerical CDS region. Crimson box, UTR regions.