Summary of the AS-NMD candidates.

†Percentage of the total number of known genes based on Ensembl build 52.
††Percentage of retained introns whose length is a multiple of 3.
*Orthology was based on the relationship one-to-one between a human transcript and a transcript from the other genome according to Ensembl annotation.
∇Significant by a hypergeometric probability test with P ≤10−10. We calculated the probability of picking the observed number of AS-NMD candidates in the other mammals that are conserved in human, from the total population of human genes.