Soeroso, N.N. et al. 2024. Protein Programmed Death-Ligand 1 Expression in Non-Small Cell Lung Cancer (NSCLC) and Its Correlation to Smoking Status in North Sumatera Population. Sumatera Medical Journal. 7, 2 (May 2024), 57–64. DOI:https://doi.org/10.32734/sumej.v7i2.15289.