PDCD1 and neoplasm: Clustering analysis revealed seven different phenotypes characterizing OT-I T cells in PDAC primary tumour: cycling T cells (clusters 1 and 3), terminally exhausted T cells expressing inhibitory molecules (for example Havcr2 and Pdcd1) (cluster 0), effector T cells expressing inflammatory cytokines (for example Ifng and Tnfa) (cluster 2), precursor exhausted T cells (Tpex) that express Tcf7 and Slamf6 (cluster 4)33 and effector memory T cells expressing Klf2, Tcf7 and Gzma (cluster 5) (Extended Data Fig. 2b,c).