Lung cancer is an exceedingly prevalent form of cancer, frequently diagnosed, and holds the unfortunate distinction of being the primary cause of cancer-related fatalities on a global scale.1 Non-small cell lung cancer (NSCLC) accounts for 85 % of all lung cancer cases and has a low 5-year survival rate.2 Previous studies have revealed that CircDONSON plays a pivotal role in promoting the growth and invasion of gastric cancer by activating the NURF complex-dependent transcription factor SOX4.3 However, the function significance of CircDONSON in lung cancer remains unexplored. Mechanistically, we demonstrate that CircDONSON interacts with HNRNPC and subsequently inhibits the downstream MAPK signaling pathway. To summarize, our study demonstrates that CircDONSON acts as a tumor suppressor in lung cancer and exhibits potential as both a prognostic marker and therapeutic target for NSCLC.