FOXP3 and neoplasm: In this panel, PD-L1 (immune checkpoint), CD3 (T cells), CD8 (cytotoxic T cells), CD163 (histiocytes/macrophages), and FoxP3 (regulatory T cells) were analyzed in epithelial tumor (CK+) and surrounding stromal (CK-) compartments, respectively, across 3 different tumor types (Fig 5).