CD8A and neoplasm: A common criticism of mathematical models is that biological components, like myeloid-derived suppressor cells (Marvel and Gabrilovich, 2015; Parker et al., 2015), or interactions between these components, like suppression of cell proliferation by IFNG produced by CD8+ T cells (Matsushita et al., 2015), thought to play important roles within the tumor microenvironment are not explicitly represented by the model topology.