RNA editing events influence gene expression and phenotypic manifestation Combining computational mining of big data with experimental testing in the lab, researchers at Children's Hospital of Philadelphia (CHOP) have identified RNA editing events that influence gene expression and, in turn, the phenotypic manifestation of that expression. In analyzing so-called A-to-I RNA editing, in which the adenosine of an RNA molecule is chemically modified into an inosine, the researchers describe how a single nucleotide change by RNA editing can have large downstream effects. The findings were published today in Genome Biology. Millions of A-to-I RNA editing sites have been identified across the human transcriptome, but the functions of most RNA editing events are unknown. Understanding how RNA editing affects gene expression and phenotype could help us unravel the genetic basis to many human conditions."