MKI67 and neoplasm: To evaluate the spatial distribution of endogenous T cells within the TME, multiplex immunofluorescence (MIF) was performed on D14 and D23 tumors using a 7-plex panel (CD4, CD8, FOXP3, granzyme B [GzmB; activation], Ki67 [proliferation], PanC/K [tumor marker], and DAPI [DNA marker]) (Figure 5A).