Table 1.

Comparison of several important features of mRNAs and long noncoding RNAs (lncRNAs) based on GENCODE v7 catalog of human transcripts*.

Feature	mRNAs	lncRNAs
Median transcript length	2453 nt	592 nt
Median number of exons	3	8
Expression levels	Higher	Lower
5’ end supported by CAGE	55%	15%
3’ end supported by polyA signal	51%	39%
Tissue specificity	Lower	Higher
Subcellular localization	Mostly cytoplasmic	Mostly nuclear

*The data shown in Table 1 are taken from Derrien et al. (2012).