ADAT2 is the catalytic subunit of the heterodimeric ADAT2/ADAT3 tRNA deaminase complex that catalyzes adenosine-to-inosine (A-to-I) conversion at position 34 (wobble position) of the anticodon in eukaryotic tRNAs 1. This modification expands codon recognition capacity, allowing inosine to pair with uracil, cytosine, and adenine at the third mRNA codon position 2. The ADAT3 regulatory subunit positions the tRNA anticodon stem-loop in the ADAT2 active site through conformational rotation of its N-terminus 3. Proper ADAT2/ADAT3 catalytic activity is essential for radial migration of projection neurons during cortical development; variants impairing complex function cause severe neurodevelopmental disorders characterized by intellectual disability 234. Beyond neurodevelopment, ADAT2/3 genes are commonly amplified and overexpressed in multiple tumor types including liposarcoma, where the complex promotes cancer cell growth by facilitating translation of codon-biased mRNAs enriched in codons dependent on A-I tRNA editing 5. Additionally, ADAT2 expression correlates with breast cancer prognosis 6. These findings establish ADAT2 as critical for both normal neural development and cellular processes dysregulated in cancer.