An investigation of early cytotoxic lymphocyte infiltration in solid tumors led to the discovery that reduction in C-X3-C Motif Chemokine Ligand 1 & receptor 1 (CX3CL1-CX3CR1) restricts cytotoxic cells from the solid-tumor bed, contributing to tumor evasion (50). This evidence concerns the gene CX3CL1 and neoplasm.