This enrichment, in the case of both Foxp3− and Foxp3+ CD4+ T cells, was highly significant compared with the spleen and lymph nodes, pointing to a continuous chemokine-mediated recruitment of these T cells to the tumours, a conclusion supported by the observation that migration of adoptively transferred T cells to tumours was inhibited by administration of Pertussis toxin. Here, CD4 is linked to neoplasm.