PTPN2 and neoplasm: Consistent with our previous studies (Wiede et al, 2011), PTPN2‐deficient CD25hiFoxP3+ regulatory T cells (Tregs) were increased rather than decreased in AT‐3‐OVA tumours (Appendix Fig S2D) and their activation was moderately enhanced (Appendix Fig S2E) precluding the repression of tumour growth being due to defective Treg‐mediated immunosuppression.