The factors that can contribute to the increased susceptibility of pleural effusion CD8+ T-cells to AICD are the following: (a) gangliosides released by lung tumor or stromal cells, given that these molecules sensitize activated T-cells to apoptosis in vitro [111, 112]; (b) diminished levels of CD3ε in CD8+ T-cells may lead to the dysfunction of CD8+ T-cell responses and enhanced T-cell apoptosis [80]; (c) the chronic presence of tumor antigens and damage associated molecular patterns (DAMPs) secreted by tumor or stromal cells in the pleural compartment. This evidence concerns the gene CD8A and Pleural effusion.