NOP2/Sun domain family, member 2 is a protein that in humans is encoded by the NSUN2 gene. Alternatively spliced transcript variants encoding different isoforms have been noted for the gene. The protein is a methyltransferase that catalyzes the methylation of cytosine to 5-methylcytosine (m5C) at position 34 of intron-containing tRNA (Leu) (CAA) precursors. This modification is necessary to stabilize the anticodon-codon pairing and correctly translate the mRNA. NSUN2 is also localized on mitochondria and is capable of introducing post-transcriptional modifications in mitochondrial tRNAs. Mutations in this gene have been found associated to cases of Dubowitz-like syndrome.