CD8 T cell numbers in the peripheral blood are not impacted by loss of MHCI expression in cancer cells (mean CD8 T cell number/μl peripheral blood d7 PK5L1940 1010 CD8/μl PK5L1940 B2M−/− 1024 CD8/μl p = 0.87), indicating that there is no systemic loss of CD8 T cells in these mice. Here, B2M is linked to cancer.