CTLA4 and neoplasm: Four T cell clusters appeared in both tumour and paratumour tissues (Figures 4A and B), including Tregs expressing FOXP3 and CTLA4,26 CD8+ CTLs expressing CST7, PD1+CD4+ T cells expressing PDCD1,8 and CD4+ TMs (memory T cells) (Figures 4C and S3B).