Fig. 1
From: Long non-coding RNA HEIH: a novel tumor activator in multiple cancers
Schematic representation of ncRNAs of different lengths. Small ncRNAs are shorter than 200 nucleotides, including miRNAs (21–23 nucleotides), piRNAs (26–31 nucleotides), snoRNAs (60–140 nucleotides), and snRNAs (~ 150 nucleotides). In contrast to small ncRNAs, lncRNAs are longer than 200 nucleotides, reaching up to thousands of nucleotides of length. CircRNAs are a peculiar group of endogenous lncRNAs molecules, consisting of at least a few hundred nucleotides