FIRM integration formalism. This figure summarizes the plan devised for the development of FIRM. The oval at the top represents the method of building dynamic models that was employed to construct FIRM. At each step, the subset model included can be seen on the left, and the major cell populations covered in each step is outlined on the right. MK refers the Marino-Kirschner model (including resting macrophages MR, activated macrophages MA, infected macrophages MI, T-helper 1 cells Th1, T-helper 2 cells Th2, dendritic cells DC and pathogen ), DB refers to the DeBoer et al. model (including resting macrophages MR, activated macrophages MA, T-helper 1 cells Th1, cytotoxic T-cells TC and Tumor ), and BL refers to the Bell model (which includes naïve B-cells B, activated B-cells BA, memory B-cells BM, plasma B-cells BP and Antigen ). “Pathogen” indicates bacterial infection, while “Antigen” refers to viral or other small antigen infection. The partial overlap of the models provides a roadmap to integration, which however needs to take into account the diversity of formulations used in the models to account for essentially the same immune response features.