Fig. 1From: Transfer RNA-derived small RNA: an emerging small non-coding RNA with key roles in cancerBiogenesis and classification of tsRNAs. tsRNAs can be divided into two species. The first type is tRFs, which can be divided into four subclasses, tRF-1, tRF-3, tRF-5, and i-tRF (tRF-2), based on the position of cleavage. The second type is tiRNAs, classified into 3′ tiRNA and 5′ tiRNABack to article page