Fig. 2.

Regulatory T cells in gastric cancer patients are activated and have the potential to infiltrate tumor tissue (staining Panel-2). PBMCs from 26 gastric cancer patients (filled circles) and eight healthy donor samples (filled triangles) were analyzed with regard to frequency of CD4⁺ T cells (a) and Tregs of CD4⁺ T cells (b). Resting Tregs were determined by CD45RA positivity (c). Fine dissection of Tregs shows activated FoxP3^hiCD45RA⁻ (d) and resting FoxP3^loCD45RA⁺ (e) subpopulations. Tumor-infiltrating Tregs were identified by cell surface marker staining CD103 (f). The horizontal black lines represent median. p values were obtained with a Mann–Whitney test, *p < 0.05; **p < 0.01. HD healthy donors, n.s. not significant, P patients, Treg T regulatory cells, PBMCs peripheral blood mononuclear cells