Non-coding RNAs are
A non-coding RNA (ncRNA) is a functional RNA molecule that is transcribed from DNA but not translated into proteins. Epigenetic related ncRNAs include miRNA, siRNA, piRNA, and lncRNA. In general, ncRNAs function to regulate gene expression at the transcriptional and post-transcriptional level.
siRNA
miRNA
tRNA
mRNA
Metabolism of nucleic acids