CX3CL1 and neoplasm: Indeed, however, taking advantage of the fact that CX3CL1 seems to be present in more than 80% of colorectal tumors but showed a significantly lower expression level in the normal colon mucosa [22,23], ectopic expression of its receptor CX3CR on ex-vivo-expanded T cells designated for adoptive T cell immunotherapy has been discussed and successfully validated in vivo in a humanized CRC mouse model as a strategy to guide the transferred T cells from the peripheral circulation into the tumor tissue [22].