Noncoding RNAs play multiple roles in controlling gene expression​? ncRNAs?

- A small fraction of DNA codes for proteins, and a very small fraction of the non-protein-coding DNA consists of genes for RNA such as rRNA and tRNA​ - In the past, genes that did not encode a protein product or known functional RNA were considered “junk DNA.”​ However, some genomic studies have cast doubt on this description​ - Roughly 75% of the human genome is transcribed in at some point in any given cell​ - At least some of the genome is transcribed into noncoding RNAs (ncRNAs)​ - Researchers are uncovering more evidence of biological roles for these ncRNAs every day​ - This represents a major shift in the thinking of biologists​