Acting beyond its canonical RNA-editing activity, ADAR1 promotes tumor progression through several distinct mechanisms: it sustains cancer stemness and metastatic potential via WNT/β-catenin signaling, inhibits ferroptosis through the miR-335-5p/Sp1/GPX4 axis, and suppresses innate immune activation in cooperation with RNA helicases such as DHX9. The gene discussed is GPX4; the disease is cancer.