LN stromal cultures exclusively express LEC markers by the fourth passage. Immunofluorescent staining of cultured primary mouse LN cells at P4. Cells were plated in 12-well plates (40,000 cells/well), and immunostained for Prox1 (A), 10.1.1 (E), podoplanin (C), and CD31 (B), but not LYVE-1 (G), MECA-32 (D), ER-TR7 (F), or SMA (H), shown in the left panels. Nuclear DAPI staining is shown in the right panels. Adjacent images (A and B; C and D; E and F; and G and H) are of co-stains of the same field of cells. Staining was repeated on three independent cell isolates; representative images are shown.