Mouse liver, under patrol of immune cells

A mouse liver whose cells have been made to glow. The yellow comes from a fluorescent protein delivered into them by a harmless engineered virus — a standard way of getting cells to announce themselves with light. Scattered among the big liver cells are a few much smaller ones in magenta: T cells, the immune system's patrol, going about their rounds.

🟨 Liver cells, glowing with Venus (a yellow fluorescent protein) 🟪 Immune cells (T cells, CD3) 🟦 DNA