ADAR (adenosine deaminase RNA specific) is an RNA-editing enzyme that catalyzes the hydrolytic deamination of adenosine to inosine in double-stranded RNA (A-to-I RNA editing) 1. This modification affects gene expression through multiple mechanisms: altering amino acid sequences when edited inosines are read as guanosines during translation, modifying splice site recognition, changing RNA stability, and influencing microRNA processing 1. ADAR targets both cellular substrates (including neurotransmitter receptors GRIA2, HTR2C, and GABRA3) and viral RNAs, exhibiting either proviral or antiviral effects depending on the pathogen 2. Mechanistically, ADAR1 prevents autoinflammation by suppressing spontaneous activation of dsRNA sensors including MDA5, PKR, and ZBP1 3. The enzyme's Z-nucleic acid-binding domain is crucial for preventing ZBP1-mediated cell death by editing endogenous Alu elements 3. Clinically, ADAR1 deficiency causes Aicardi-Goutières syndrome, a severe inflammatory disorder 3. In cancer, tumor-derived interferons create chr1 signaling states that render ISG-positive tumors vulnerable to ADAR loss, suggesting therapeutic potential 4. ADAR's role in immune silencing and its function as both enzyme and scaffold make it an attractive target for cancer immunotherapy 5.