Stalactite in the colon
In multiplex immunofluorescence, the colon cancer microenvironment appears like a cave of glowing stalactites — the epithelial glands (pan-CK⁺, white) descend like crystalline columns, while immune cells cascade beneath them in structured layers. CD8⁺ (cyan) T cells cling to the epithelial edges like mineral deposits, CD4⁺ (green) and FOXP3⁺ (yellow) cells accumulate below them, and macrophages (orange) and B cells (red) fill the deeper stromal “floor.” This “stalactite” formation reflects the directional infiltration of immune cells into glandular structures, illustrating a vertical immune gradient along the tumor–stroma axis in colon cancer.