GFP positive cells express pericyte markers.

<p>(A) All GFP positive cells within the GL261 tumor are clearly positive for PDGFR-β. (B) Out of all PDGFR-β positive cells within the tumor, 57 ± 6.6% are host-derived GFP positive cells (n = 3, mean ± SEM). (C) A proportion of the cells are positive for the activation marker NG2. The majority of the GFP positive cells lack expression of the mesenchymal stromal cell marker CD13. (D) GFP positive cell at the tumor border expressing CD13. (E) The majority of the cells weakly express the pericyte marker α-SMA. Scale bar is 500 μm in the low magnification images and 20 μm in the high magnification images.