Fig. 1
From: Piwi-interacting RNAs in cancer: emerging functions and clinical utility
Selected types of small and long non-coding RNAs. Non-coding RNAs show diversity in size and function. The small non-coding RNA category (20–35 bp) includes: microRNAs (miRNAs), tRNA-derived fragment (tRF), PIWI-interacting RNAs (piRNAs), C/D snoRNA-derived RNA (sdRNAs), and small interfering RNAs (siRNAs). The long non-coding RNA category (>200 bp) includes promoter associated long RNAs (PARs), transcribed ultraconserved regions (T-UCR), long non-coding RNAs (lncRNAs), pseudogenes, and antisense RNAs (asRNAs). piRNAs (red line) are larger than other small RNAs and, unlike most of the other small RNA (with the exception of snoRNA), are functionally active both the nucleous and the cytoplasm