CCL21 and neoplasm: Immune cells mainly included macrophages (CD68+), nonimmune cells mainly included tumor cells (ROS1+), fibroblasts (COL1A2+), alveolar type 2 epithelial cells (SFTPC+), alveolar type 1 epithelial cells (AGER+), epithelial cells (EPCAM+), endothelial cells (CD31+), lymphoid endothelial cells (CCL21+), and aerocyte endothelial cells (SOSTDC1+) (Figure 1E–G).