Although we observed a trend for preferential migration of Treg cells to the tumour and a significant enrichment in the spleen compared with the lymph nodes (Fig.1a) we found that Foxp3+ T cells recovered from the tumour were not enriched within the recovered CD4+ T-cell population compared with the input population (Fig.1b), thereby indicating that Foxp3+ T cells are not more likely than Foxp3− T cells to migrate to the tumour mass. The gene discussed is CD4; the disease is neoplasm.