We found that many large introns are removed by multiple recursive splicing steps, ... These steps involve the sequential excision of smaller subfragments. Our work also indicates that most recursive splicing events leave no clues in the final mRNA. This is why they have not been detected before now.  -   Javier Lopez     Quotes
We found that many large introns are removed by multiple recursive splicing steps, ... These steps involve the sequential excision of smaller subfragments. Our work also indicates that most recursive splicing events leave no clues in the final mRNA. This is why they have not been detected before now. Javier Lopez