RNA editing is a widespread post-transcriptional molecular phenomenon that can increase proteomic diversity, by modifying the sequence of completely or partially non-functional primary transcripts, through a variety of mechanistically and evolutionarily unrelated pathways . Editing by base substitution has been investigated in animals, plants and viruses . In human, the A-to-I substitution is the most frequent editing event, carried out by members of ADAR (adenosine deaminases acting on RNA) family . Such alterations can be predicted by computational analyses based on the alignment of mRNA/EST sequences onto the genome of origin . Recent high-throughput sequence technologies offer the unique opportunity to study entire transcriptomes in a variety of experimental conditions. Massive RNA sequencing, therefore, may facilitate the investigation of post-transcriptional mechanisms occurring herein.
In order to detect A-to-I editing sites in human supported by transcript data obtained by RNA-Seq experiments we developed the web application ExpEdit. In our system, mapping data (in SAM/BAM format) or directly sequence reads (in FASTQ or SRA format) can be provided as input to carry out a comparative analysis against a large collection of known editing sites collected in DARNED database  as well as other user-provided potentially edited positions.