A study with a large cohort of 627 colorectal cancer (CRC) specimens by Takeda et al. revealed that adenosine deaminase acting on RNA (ADAR), the key enzyme involved in A-to-I RNA editing, was upregulated in both cancer cells and cancer-associated fibroblasts, which increased the RNA edition level of antizyme inhibitor 1 (AZIN1). Here, ADAR is linked to cancer.