Immunofluorescence Staining

The dewaxing and hydration steps for the paraffin sections are the same as those described above. The tissue was treated with 1% TritonX‐100 for 20 minutes and blocked with 10% goat serum at room temperature for 1 hour. The primary antibodies were LYVE‐1 (1:100, Rabbit, 3107EA18; Invitrogen, Thermo Fisher Scientific), podoplanin (PDPN; 1:100, Rabbit, ab109059; Abcam), PROX1 (1:100, Rabbit, 11‐002p; AngioBio). The next day, tissues were incubated with fluorescein isothiocyanate (FITC)‐conjugated donkey anti‐rabbit secondary antibodies (1:1000; Invitrogen), and diamidino‐phenyl‐indole staining at was performed room temperature in darkness for 1 hour. Specimens were imaged on a Leica confocal microscope (Leica).