CD4 and melanoma: Accordingly, our group previously used MILAN – an imaging/antibody-based single-cell proteomics method - to functionally study tissue architecture, thereby redefining the TIL infiltrate in primary melanoma into a functional classification with an improved prognostic value as compared to the dogmatic morphological classification (44) and described a higher level of interaction between melanoma cells with active CD8+ and CD4+ T cells in patients responding to anti-PD-1 as compared to the non-responding patients (87).