IHH and lymphoma: demonstrated that genetic deletion of CCR7 in the syngeneic Eμ-Myc mouse lymphoma model was sufficient to exclude CCR7-deficient lymphoma cells from the T cell zone whereas wild-type lymphoma cells lodged to the stroma in close proximity to CD40L-expressing CD4+ T cells, DCs, and gp38+ fibroblastic reticular cells (FRCs), these latter providers of CCR7 ligands and the anti-apoptotic Indian hedgehog protein (Ihh) (34, 142).