AT-3-OVA mammary tumour cells (1x106) were injected into the fourth inguinal mammary fat pads of female Ly5.1+ mice. Seven days after tumour injection FACS-purified 2x106 naïve CD8+CD44loCD62Lhi lymph node T cells from Ly5.2+;OT-1;Ptpn2fl/fl versus Ly5.2+;OT-1;Lck-Cre;Ptpn2fl/fl mice were adoptively transferred into tumour-bearing Ly5.1+ mice. Tumour-bearing Ly5.1+ mice were monitored for a) tumour growth over 21 days 