Ng2-cre–mediated recombination in cerebral vascular mural cells. (Top) Representative images of EGFP (green signal) and PDGFRB (red signal) immunofluorescence in brains from control (Ng2-cre^-) and NG2-mT/mEGFP mice that were deficient for Phd2 (Ng2-cre⁺). NG2-mT/mEGFP-Phd2^−/− mice are phenotypically normal and did not develop polycythemia. (Bottom) Magnification shows coexpression of PDGFRB (red signal) and EGFP (green signal) in NG2 cells.