Biology and clinical significance of the TME in CHL. This schematic shows a selection of the interactions between the HRS cells and cells in the microenvironment. The prognostic significance of components of the microenvironment as detected by IHC is shown. Increased galectin 1 in the microenvironment is also associated with adverse prognosis. Therapeutic strategies that target the cross-talk between the HRS cells and the TME are shown in black boxes.