PDCD1 and cancer: Treatment-expanded tumor T cell clones (CD103+ZNF683+GZMB+PD-1+CTLA-4+) in responding patients recognized cancer-specific antigen MAGEA1.The frequency of activated blood CD8+ T cells (CD38+HLA-DR+), notably pre-treatment PD-1+ KLRG1- T cells, was strongly associated with intra-tumoral pathological response.