Fig. 3
From: Expression of immune checkpoints on circulating tumor cells in men with metastatic prostate cancer
Representative patient CTCs stained for cytokeratin (CK), 4′,6-diamidino phenylindole (DAPI), CD45 (marker of leukocytes), and the immune checkpoint ligand of interest ([A] PD-L1, [B] PD-L2, [C] B7-H3, or [D] CLTA-4). CTCs are defined as being CK-positive, DAPI-positive, and CD45-negative. Orange boxes are indicators from the CellTracks Analyzer II that a cell was identified as marker-positive