The repression of tumour growth was accompanied by an increase in Lck‐Cre;Ptpn2fl/fl OT‐1 T cells in the draining lymph nodes of the tumour‐bearing mammary glands (Appendix Fig S3A) and a marked increase in tumour‐infiltrating Lck‐Cre;Ptpn2fl/fl OT‐1 T cells (Fig 2B; Appendix Fig S3B). The gene discussed is LCK; the disease is neoplasm.