Phenotypic and functional changes with clinical stage. (A) Euclidean distance between the “average CD4⁺ TIL phenotype” and that of individual CD4⁺ TIL, CD8⁺ TIL, and MF tumor phenotypes. This demonstrates that the MF tumor phenotype diverges markedly from that of the TIL populations. (B) Euclidean distance between the CD4⁺ TIL phenotype and that of the MF tumor phenotype in relation to the clinical stage of the disease. Early-stage disease was defined as patch and plaque, whereas late-stage disease included only the tumor subtype. The MF phenotype is seen to diverge most markedly from that of the TIL populations in biopsies from patients with late-stage disease. (C) CD107a surface expression is higher in TILs compared with matched blood, suggesting recent microenvironment degranulation. (D) CD107a surface expression is lower with increasing clinical stage. (E) Cytokine production by stage, demonstrating a general trend for decreased cytokine production in later stages, significant in IL-17 and IL-10 in CD4 TILs.