(c) Signaling molecules also play a role, as the density of tumor-infiltrating T cells is negatively associated with expression of VEGF, B7-H1/PD-L1 and endothelin B receptor by tumors [5], [11], [68] and positively associated with expression of the chemokines CXCL9, CCL21, CCL22, CCL2 and CCL5 [5], [28], [69]. Here, CCL21 is linked to neoplasm.