For the T cell panel, FAUST identified a single subcluster of CD8+ T cells, and four CD4+ Treg (CD25+ CD127−) phenotypes marked by expression of ICOS with combinations of PD-1, TIM3 and HLA-DR as being enriched in HNSCC (Extended Data Fig. 2a–c). Here, PDCD1 is linked to head and neck squamous cell carcinoma.