Figure 1.

Major targets of cytokines used in clinical trials directed at immune cells involved in adaptive and innate immunity. Blue arrows indicate recruitment and differentiation. Red arrows indicate activation and expansion. Gray arrows indicate inhibition. IL-22 has been excluded here as its clinical trials have targeted its growth-factor properties and not its immunostimulant properties. TNF-related apoptosis-inducing ligand (TRAIL) is also excluded as its non-apoptotic role in immune-cells is not clearly understood.^[35] The effects of IFN-λ are primarily on epithelial cells.^[36]