AI-based modeling has proven to be invaluable in identifying key regulatory interactions governing immune responses, including cytokine and chemokine signaling at infection or tumor sites, antigen-presenting cell (APC) activation and migration, antigen presentation to T cells, and CD4+/CD8+ T-cell cooperation with dendritic cells in infected or tumor tissues and lymph nodes (Terry and Chaplain, 2011). Here, CD4 is linked to infection.