To elucidate the role of MHC in the bystander activation of memory CD8 T cells, the authors adoptively transfer VSV-specific CD8 memory T cells to congenic MHC class I-sufficient or -deficient hosts followed by infection with unrelated infection (Listeria monocytogenes—Lm) showing a reduction in IFNγ expression in MHC-I-deficient mice compared to WT mice (14). This evidence concerns the gene HLA-C and infection.