Interactions among cHL cells and the microenvironment. Proposed role of the CCL5/CCR5 axis in Hodgkin Lymphoma leading to tumor cell proliferation and microenvironment formation. CCL5 produced by cHL cells may represent an autocrine growth factor. CCL5 secreted by T cells or fibroblasts may represent a paracrine growth factor. CD40L increases CCL5 secretion by cHL cells and they induce fibroblasts to secrete CCL5. CCL5 secreted by cHL (direct recruitment) or fibroblasts activated by HL cells (indirect recruitment) may in turn recruit CD4+ T cells, T-reg cells, eosinophils, and mast cells.