POU5F1 and vascular neoplasm: In contrast to the non-diseased vascular rich tissue controls, benign vascular tumors and the single thrombophlebitis sample exhibited significantly increased staining (in both intensity and percentage of positive tissue) for Oct4, Nanog, Myc, and Sox2, with no statistically significant increase in antigenicity for Klf4 (Fig. 6, Additional file 2: Table S1).