Patients with low miR-34a expression levels were associated with shorter progression free survival (PFS) and overall survival (OS) compared to patients with high 34a expression (1.97 vs 6.33 months; p = 0.042 and 2.93 vs 9,60 months; p = 0.012, respectively)....findings suggest that circulating miR-34a may serve as a potential predictive biomarker in NSCLC patients treated with immunotherapy.