Immunohistochemical staining was performed using a two-step method with heat-induced antigen-retrieval procedures (14 (link)). The cancer tissues were fixed in 4% paraformaldehyde. Following dehydration, the tissue was sliced and blocked in 10% BSA (Sigma-Aldrich; Merck KGaA). The following primary antibodies were used: Rabbit anti-human CCBE1 monoclonal antibody (cat. no. HPA041361, 1:50-1:200; Sigma-Aldrich, Merck KGaA) and rabbit anti-human LYVE1 monoclonal antibody (cat. no. ab33682, 1:100; Abcam). The slices (20 µm) were incubated with horseradish peroxidase-conjugated secondary antibodies (1:100, peroxidase conjugated goat anti-rabbit IgG, TA130023; OriGene Technologies, Inc.) at room temperature for 2 h. The primary antibody was applied in the negative control. The images were visualized by light microscope (Olympus Corporation, Tokyo, Japan).