From: High frequency of intron retention and clustered H3K4me3-marked nucleosomes in short first introns of human long non-coding RNAs
IR present
IR absent
M present
57
10
M absent
52
81
Median intron length (bp)
192
2181
Average intron size (bp) ± standard error
354 ± 67
5323 ± 841
Frequency of 1st intron
73 (67%)
24 (26%)