Consistent with our previous findings, localized administration of a naturally occurring attenuated NDV led to an inflammatory response, resulting in the local and distant tumour infiltration with CD8+ and CD4+FoxP3− conventional T cells (Tcon), with significant reduction in the relative percentage of CD4+FoxP3+ regulatory T cells (Tregs; Fig. 1b–e). This evidence concerns the gene FOXP3 and neoplasm.