Pericytes are dissociated from ECs on treatment with PDGFR inhibitors. Treatment of RIP1-Tag2 mice with imatinib or CP-673,451 induces pericyte detachment in PNET (arrows). RIP1-Tag2 mice were treated with imatinib (150 mg/kg a day; n = 10) or CP-673,451 (50 mg/kg a day; n = 5) for 5 days by oral gavage. Pictures show immunostaining for CD31 (green) and NG2 (red) on cryosections. Arrows indicate tightly associated (control) or dissociated (imatinib and CP-673,451) pericytes in the tumor vasculature. Dotted line marks tumor:exocrine pancreas boundary. Cell nuclei (DAPI), blue. Boxes indicate areas shown in higher magnification in the right panel. Original magnification, 200×. The panels are representative of at least 5 fields in 5 tissue sections taken from 5 mice.