Differential expression analysis of pre- and post-treatment tumor-infiltrating MAIT cells revealed upregulation of the activation marker HLA-DRB1, the cytotoxic effector GZMH, and the chemokines CCL4 and CCL5 following anti-PD-1 therapy in both types of cancer (Figures 4E,F). Here, HLA-DRB1 is linked to cancer.