Spatial proteomic profiling (43-plex IMC) of serial biopsies from a neoadjuvant ICB trial in TNBC revealed that response is driven by multicellular spatial organization—specifically pre-treatment proliferating CD8+TCF1+ T cells and MHCII+ cancer cells, alongside on-treatment expansion of granzyme B+ T cells in responders versus CD15+ cancer cells in non-responders—demonstrating that early on-treatment tissue features combined with baseline signatures optimally predict response (56). Here, FUT4 is linked to cancer.