tiRNAs & tRFs are a class of small molecular noncoding tRNA derived from precise
processing of mature or precursor tRNAs. Most tiRNAs & tRFs described originate from
nucleus-encoded tRNAs, and only a few tiRNAs and tRFs have been reported. They have
been suggested to play important roles in inhibiting protein synthesis, regulating gene expression,
priming viral reverse transcriptases, and the modulation of DNA damage responses.
However, the regulatory mechanisms and potential function of tiRNAs & tRFs remain poorly
understood. This review aims to describe tiRNAs & tRFs, including their structure, biological
functions and subcellular localization. The regulatory roles of tiRNAs & tRFs in translation,
neurodegeneration, metabolic diseases, viral infections, and carcinogenesis are also discussed
in detail. Finally, the potential applications of these noncoding tRNAs as biomarkers and gene
regulators in different diseases is also highlighted.