of lncRNA are supported, respectively, indicating that the majority of transcripts are incomplete. Interestingly lncRNA transcripts have an unusual exon structure compared with protein-coding transcripts, with their distribution peaking at two and five exons, respectively (see Fig. 2). This lower number does not appear to be an artifact or the product of incomplete annotation but most probably is a bona fide characteristic of the lncRNAs, as it is also observed in potential lncRNA models identified using the Illumina Human Body Map 2.0 (HBM) RNA-seq data generated in 2010 on HiSeq 2000 instruments (described below), which are not built from partial ESTs.
