Tumor-specific CD8 T cells play a prominent role in antitumor immunity. However, these cells regularly enter a state of exhaustion due to chronic antigen stimulation within the tumor microenvironment.

It's a good news, bad news scenario for exhausted T cells in chronic infections. Multiple groups of investigators reported in the July 26, 2021, online issue of Nature Immunology that even after a chronic hepatitis C virus infection was cured, T cells that had become dysfunctional during the infection retained epigenetic "scars" that prevented them from becoming fully functional memory T cells.

It's a good news, bad news scenario for exhausted T cells in chronic infections. Multiple groups of investigators reported in the July 26, 2021, online issue of Nature Immunology that even after a chronic hepatitis C virus infection was cured, T cells that had become dysfunctional during the infection retained epigenetic "scars" that prevented them from becoming fully functional memory T cells.