The cap-to-tail guide to mRNA turnover

The levels of cellular messenger RNA transcripts can be regulated by contro lling the rate at which the mRNA decays. Because decay rates affect the exp ression of specific genes, they provide a cell with flexibility in effectin g rapid change. Moreover, many clinically relevant mRNAs - including severa l encoding cytokines, growth factors and proto-oncogenes - are regulated by differential RNA stability. But what are the sequence elements and factors that control the half-lives of mRNAs?