Flow cytometry analysis of the numbers of hydrothorax Foxp3+ T cells in tuberculous and malignant hydrothorax patients. The peripheral blood and hydrothorax mononuclear cells were stained with anti-CD4 and anti-CD25, fixed and permeabilized, followed by staining with anti-Foxp3. The cells were first gated on living lymphocytes and on CD4+ cells, and the numbers of blood and hydrothorax CD4+CD25+Foxp3+ and CD4+CD25−Foxp3+ T cells were characterized by flow cytometry analysis. Subsequently, the numbers of hydrothorax CD4+CD25+Foxp3+ and CD4+CD25−Foxp3+ T cells were stratified, according to the levels of hydrothorax ADA = 45 in tuberculous hydrothorax patients and CEA = 20 in malignant hydrothorax patients. Data shown are representative charts and expressed as the means of individual subjects. a Representative charts; b the numbers of CD4+CD25+Foxp3+ T cells; c the numbers of CD4+CD25−Foxp3+ T cells. d stratification analysis of the numbers of CD4+CD25+Foxp3+ T cells. e Stratification analysis of the numbers of CD4+CD25−Foxp3+ T cells. The horizontal lines show the median values of individual groups.