CX3CR1 and neoplasm: For the most part, we found either no significant difference in the proportions of Foxp3− and Foxp3+ CD4+ T cells expressing a particular chemokine receptor (CCR3 and CCR5) or, in the case of some chemokine receptors, we found a significant difference in favour of Foxp3− CD4+ T cells (CCR1, CCR2 and CX3CR1); findings that are compatible with our observation that following adoptive transfer there was no evidence for preferential migration of Foxp3+ T cells to the tumour mass.