CCL21 and neoplasm: Although chemokines such as CCL3, CCL4, CCL5, CCL19, CCL20, CCL21, and XCL1 can contribute to tumor progression by modulating tumor cells and protumorigenic elements of the tumor microenvironment—including fibroblasts, endothelial cells, and immunosuppressive immune cells—they are also recognized for their ability to recruit cDCs and potentially enhance antitumor immunity [71, 72].