FASLG and lung cancer: Moreover, in the malignant pleural effusions of lung cancer patients, the upregulation of the Fas ligand (FasL), TNF-related apoptosis-inducing ligand (TRAIL) expressions, and the low B-cell lymphoma-2 (Bcl-2) expression cells may be responsible for the activation-induced cell death that impairs the antitumor function of CD8+ T cells (68, 71).